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THE

SCIENTIFIC TRANSACTIONS

OF THE

ROYAL DUBLIN SOCIETY.

VOLUME IV. — SERIES II.

DUBLIN:

PUBLISHED BY THE EOYAL DUBLIN SOCIETY.
PRINTED AT THE UNIVERSITY PEESS, BY PONSONBY AND WELDRICK,

PEINTEBS TO THE SOCIETY.

1888-1892.

CONTENTS.

The date of Reading will be found prefixed to each Paper. The date of Publication, as inserted in the following Table
of the Contents of thisVolume, is that when the Paper was laid in a printed form before the Society ; or when, during
the Vacation, it was forwarded to the Society's Booksellers.]

BOEDDICKER, OTTO, Ph.D. page

Observations of the Planet Jupiter, made with the Eeflector of Three Feet Aperture,

at Birr Castle Observatory, Parsonstown (Plates XXIV. to XXX.), . . .271

[Published March, 1889.]

Lunar Radiant Heat, Measured at Birr Castle Observatory, during the Total Eclipse of
January 28, 1888. With an Introduction by the Earl of Rosse, K.P., LL.D.,
F.R.S., &c, President of the Royal Dublin Society (Plates LIII. to LV.), . . 481

[Published July, 1891.]

BRADY, GEORGE STEWARDSON, M.D., F.R.S., and the REV. ALFRED M. NORMAN,
M.A., D.C.L., F.L.S.

A Monograph of the Marine and Freshwater Ostracoda of the North Atlantic, and of

North-Westem Europe. Section I. — Podocopa (Plates VIII. to XXIII.), . . 63

[Published March, 1889.]

DAVIS, JAMES W., F.G.S., F.L.S., F.S.A., &c.

On Fossil Fish Remains from the Tertiary and Cretaceo-Tertiary Formations of New

Zealand (Plates I. to VII.), 1

[Published April, 1888.]

On the Fossil Fish of the Cretaceous Formations of Scandinavia (Plates XXXVIII. to

XLVL), 363

[Published November, 1890.]

On the Fossil Fish-Remains of the Coal Measures of the British Islands. Part I. —

Pleuracanthidae (Plates LXV. to LXXIII.), . . . . - . .703

[Published November, 1892.]

183603

iv

Contents.

GRUBB, SIR HOWARD, M.A.I., F.R.S. page

The Construction of Telescopic Object-Glasses for the International Photographic Survey

of the Heavens, 475

[Published June, 1891.]

HADDON, ALFRED C., M.A., M.R.I.A.

A Revision of the British Actinia*. Part I. (Plates XXXI. to XXXVII.), . . .297

[Published June, 1889.]

HADDON, ALFRED 0., M.A., M.R.I.A., and MISS ALICE M. SHACKLETON, B.A.

A Revision of the British Actiniae. Part II.— The Zoantheaa (Plates LVIII. to LX.), . C09

[Published November, 1891.]

Reports on the Zoological Collections made in Torres Straits, 1888-1889. Actiniae.

I.— Zoantheae (Plates LXI. to LXIV.), 673

[Published December, 1891. .]

HOLT, ERNEST W. L.

Survey of Fishing Grounds, West Coast of Ireland, 1890, I. — On the Eggs and Larvae

of Teleosteans (Plates XL VII. to LIL), 435

[Published February, 1891.]

NORMAN, REV. ALFRED M. (See Beady and Norman.)

RAMBAUT, ARTHUR A.

A New Determination of the Latitude of Dunsmk Observatory, 289

[Published March, 1889.']

SCHARFF, R. P., Ph.D., B.Sc.

The Slugs of Ireland (Plates LVL, LVII.) 513

[Published July, 1891.]

SHACKLETON, MISS ALICE M., B.A. {See Haddon and Shackleton.)

STONEY, GEORGE JOHNSTONE, M.A., D.Sc, F.R.S.

On the Cause of Double Lines and of Equidistant Satellites in the Spectra of Gases, . 563

[Published July, 1891.]

SCIENTIFIC TRANSACTIONS

OF THE

ROYAL DUBLIN SOCIETY.

VOLUME IV.

I.

ON FOSSIL-FISH EEMAINS FEOM THE TEETIAEY AND CBETACEO-
TEETIAET FOEMATIONS OF NEW ZEALAND. By JAMES W. DAVIS,
F. Gk S., F. L. S., &c. (Plates I. to VII.)

[E«ad December 14, 1887.]
(Communicated by E. Perceval Wright, M.D.)

L — INTRODUCTORY.

j^/JORE than two years ago I received a request from Capt. F. W. Hutton,
Professor of Biology at Canterbury College, Christchurch, that I would
describe the remains of some Tertiary elasmobranchs found in New Zealand.
This was speedily followed by a small collection of fish-remains, which formed the
subject of a Paper read at the Geological Society, London. Immediately after
having made this communication, I received an intimation that other and larger
collections had been forwarded, and, with the permission of the Council of the
Geological Society, I was allowed to withdraw the Paper. The private collection
of J. Davies Enys, Esq., afforded some beautiful examples, collected from the
Castle Hill Station, near Canterbury. Prof. T. J. Parker sent a number of
specimens from the Otago Museum, collected by H. A. Ingles, Esq., from the
Amuri limestone of Kaikoura. Other examples obtained from the same strata by
Mr. Ingles were selected from the Museum of Canterbury College, Christchurch,
and forwarded by Prof. F. W. Hutton. To Sir Julius von Haast, whose premature

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART I. B

2 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

death we have now to lament, I am especially indebted for the loan of a very
large and important collection, consisting of many hundreds of specimens from
the Canterbury Museum, Christchurch ; I am further personally indebted to Sir
Julius for much valuable information, freely and generously imjDarted during
his visit to this country as Commissioner in connexion with the Colonial and
Indian Exhibition at South Kensington. I wish also to express my thanks to
Mr. Cheeseman of the Auckland Museum, and to Sir James Hector, Director
of the Wellington Museum, who has charge of the Geological Survey collec-
tions. The latter kindly referred me to a collection he left at the British
Museum in 1876, and forwarded the collections, consisting of a large number
of specimens from the Colonial Museum of New Zealand at Wellington, made
in connexion with the Geological Survey of the country. As on many pre-
vious occasions, it is a pleasure to acknowledge the courtesy and kind attention
always accorded by those in charge of the National Collections at the British
Museum, Natural History Department ; and to Dr. Henry Woodward and
Robert Etheredge, Esq., I tender my thanks ; to A. Smith Woodward, Esq.,
I am greatly obliged for much painstaking and most useful help.

II.— THE TERTIARY FORMATIONS OF NEW ZEALAND.

In Europe, the close of the cretaceous period was marked by a more or less
complete break in the chain of animal life : the forms, characteristic of the chalk
formation, were to a large extent replaced by others prior to the deposition of
the tertiary strata. These changes imply a long period, during which the areas
occupied by the cretaceous seas were raised so as to form shallower marine areas,
estuaries, or land. The chalk suffered an immense amount of denudation. In
England and the whole of the European area the break between the cretaceous
and succeeding strata of Eocene age is one of the most important and clearly
marked in the geological sequence of stratigraphical rocks. In other parts of the
world the change from the secondary to the tertiary formation is gradual ; and in
some instances no clear line of division, on palaeontological grounds, can be
maintained. In the United States the sequence is unbroken, and the Laramie
group of estuarine beds is regarded as holding an intermediate position between
the two, its large fauna and flora exhibiting a transitional stage. The flora is of
Eocene character, and taken together with the lacustrine constitution of the strata
confirms the determination to place it with the tertiaries. The fauna, on the
contrary, is of a mixed character, the Dinosauria are Mesozoic, and have not
hitherto been found in tertiary strata ; whilst turtles and crocodiles, along with
some genera of fishes, like Clastes and Myledaphus, are equally of tertiary types.
In America the changes of level were less rapid, and extended over much larger

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 3

areas than in Europe, and the result has been that the changes in the fauna have
been made with comparative regularity, and the violent dislocations so charac-
teristic of the European series have been avoided. In India the tertiary strata
attain a vast thickness ; in Scind the Oligocene and Miocene formations together
exceed 10,000 feet in thickness, the lower beds consisting of nummulitic lime-
stones, and presenting a marked distinction from the chalk. The lower parts are
rich in mammalian remains, and similarly to the tertiary strata of America, throw
considerable light on the ancestral derivation of some of the existing species.
The transition in the New Zealand strata is probably somewhat dubious. The
Oamaru and Pareora formations are undoubtedly tertiary ; the succeeding forma-
tion in descending order, the Waipara, is considered by the Geological Survey to
be composed of strata of transitional Cretaceo-tertiary age, whilst Professor F. W.
Hutton and Sir Julius von Haast regard the unconformity between the Waipara
and Oamaru as sufficiently distinct and important to render necessary the con-
sideration of the former group as upper cretaceous.

It is difficult to draw arbitrary lines between divisions in sedimentary rocks
which shall correspond to palasontological distinctions calculated to be of any
permanent value. The development of species, if accepted as a reliable theory,
naturally infers changes in specific characters, which point to faunal distinctions
as ephemeral, and stratigraphical epochs and periods founded on such distinctions
are liable to constant modification in consequence. Besides the evolutionary process
which affects the faunal characteristics of any given locality, there is. further
difficulty in correlating beds, with any degree of certainty, occurring in widely
separated areas, because, though the strata may be as nearly as possible of the
same age, and more or less similar in character, the fossil contents exhibit remark-
able differences. Certain important groups which are characteristically associated
with the strata of one district may be entirely absent from that of another of the
same age ; thus, the saurians and fish, so abundant in the Lias of Britain, are
unknown in American strata, whilst the beautiful series exhibiting the ancestry
of the horse found in the American tertiaries has no representative in England ;
on the other hand, again, the avian derivatives of Solenhofen and the English
Eocene are unknown to the strata of America. Instances might be multiplied to
an almost indefinite extent in every quarter of the globe. Taking this view of
the question, and bearing in mind that increase of knowledge makes deductions
from an evolutionary basis, a constantly changing quantity, it aj^pears to be a
rational plan to follow the method for classifying strata as stated by Prof. Hutton
(" Quart. Journ. Geol. Soc," vol. xli., p. 192) in the following terms : — " The
geology of a district can be studied quite irrespective of any other part of
the world ; we can group its rocks by means of unconformities (stratigraphical
and palaeontological) into systems and series, and after having made out' its
geological history, we can compare it with that of other parts of the world

B 2

4 Davis — On Fossil- Fish Remains from the Tertiary Formations of New Zealand.

by endeavouring to refer the systems and series to their probable equivalents
in Europe." This is essentially the plan adopted in the United States and
Canada, as well as in the different countries of Europe, and by English geologists
in India.

The following is the list of formations from the cretaceous upwards, for
which I am indebted to a paper by Professor F. W. Hutton, on the Geology
of New Zealand, in the " Quarterly Journal of the Geological Society," vol.
xli., p. 194:—

Recent, .
Pleistocene,

Wanganui
System,

Pare6ra
System,

Oamaru
System,

Waipara
System,

J Alluvian and iEolian deposits with j
Moa-bones and traces of Man, J

f Raised Beaches and shore deposits, ]

[ Peat mosses, with bones of Moa,
K^reru series,
Ormond series,
P^tane series,
Piitiki series,
Older Glacial Deposits,
Lignites of Ot%o, Mauukau, &c, j
Awat^re series,
Kauieri series,
Tawhiti series,
Ahurfri series,
Waitemdta series,
Brown Coal of Pomahdka, &c,
' Mt. Brown series,
Aot^a series,
Ototara series,
Turanganui series,
Coals of Walkato, Kaitangata, &c,
Amuri series,
Awanui series, (?)
Matake'a series,
Coals of Gray mouth, Pakawan, &c,

Recent.

Pleistocene.

Newer Pliocene.

Older Pliocene.

Miocene.

Oligocene.

> Upper Cretaceous.

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 5

The classification adopted by the Geological Survey Department differs from
this one in several particulars, and for the purpose of comparison it is given
here ; it is taken from the Guide to the New Zealand Geological Exhibits at
the Indian and Colonial Exhibition, London, 1886, and was prepared by Sir
James Hector, C. M. G., F. R. S., &c, Director of the Survey : —

( I. Post-Tertiary and Recent —

' a. Alluvial. b. Turbary. c. Volcanic. d. Dispersed gravels.

II. Pliocene —

a. Dispersed gravels.
d. Kereru series.

b. Napier series. c. Lignite series.

( III. Upper Miocene —

I a. Te Aute series. b. Taueru series.

IV. Lower Miocene —
a. Awatere series.

b. Pareora series.

c. Awamoa series.

/ V. Upper Eocene —

\ a. Mount Brown series. b. Oamaru series. c. Waitaki series.

VI. Cretaceo-tertiary —

a. Waitemata series. b. Ototara series. c. Mawhera series.
d. Chalk series. e. Waireka series. /. Coal series.

g. Black grit series. h. Propylite breccia series. i. Great
Conglomerate series.

VII. Lower Greensand —

a. Buller series. b. Porphyry breccia series. c. Amuri series.

The fish-remains described in this memoir are from the Waipara, Oamaru,
and Pareora systems ; they are comprised, with one or two exceptions, of sharks
and rays ; they number, of the former, twenty-four, and of the latter, four ;
besides there is one teleostean, a Sparnodus. There is also one species of
whale; a Squalodon. Of the elasmobranchs, two species of Carcharodon and
one of Notidanus have been previously described by Agassiz, and are of world-
wide distribution in tertiary strata. Several of the species of Oxyrhina and
Lamna approach nearly to some of the European forms ; but whilst recognizing
their relationship, reasons are given why they should be considered rather as
separate species than allocated with those previously described. There is,
perhaps, no group of fossil-fishes which have had so wide a geographical range
as the larger sharks, and it is consequently of especial interest to consider those
of formations scattered over the world, and to compare them with the repre-
sentatives from the systems of New Zealand. In Australia the remains of large
sharks have been found. Professor Frederick M'Coy has recorded and described
two species — Carcharodon angustidens and C. megalodon — from the Miocene Beds
of Bird Rock, near Geelong ("Prodromus Palseont. of Victoria," Decade ii.,

6 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

pi. xi., figs. 2, 3); and the Eev. J. E. Woods ("Geol. Obs. in S. Australia,"
p. 80) records the occurrence of teeth of Oxyrhina and probably Lamna.

Some remains of selachians have been recorded from the tertiary strata
of India, principally fragments of Carcharodon and Myliobatis. Sir Philip
Egerton described a series of the teeth of sharks from the Pondicherry Beds,
consisting of two species of Corax, five of Otodus, one of Oxyrhina, two of Lamna,
and two of Odontaspis ("Quart. Journ. Geol. Soc," vol. i., p. 164). The pre-
sence of Corax, a genus restricted to the chalk, and the relationship of the other
species to those already known from the chalk, led Sir P. Egerton to consider
the Pondicherry Beds of cretaceous age.

In Europe the tertiary strata cover a wide area, and are of great importance.
The "Faluns" of France, the Swiss "Molasse," and the "Crags" of England
and Belgium, are of Pliocene age ; they are also largely represented in Italy.
The cities of London, Paris, Vienna, and Berlin, are built on " Basins " of
Oligocene or Eocene strata. The selachian remains found in these beds have
received considerable attention from palaeontologists ; more particularly may be
named the recent researches of F. Noetling* in North Germany, Dr. H. B.
Geinitzf in Belgium, H. E. SauvageJ in the north of France, Dr. J. Probst§
in the Baltringen district, and R. Lawley|| in Italy.

In the list of fossils from the New Zealand strata there are eight genera of
elasmobranchs, which are all found in the tertiary strata of the Oamaru forma-
tion. Of these five are also obtained from the cretaceous of Waipara, but in each
instance they have been got from the uppermost beds of that system. In the
European strata a parallel set of circumstances is found to prevail. The genera
Galeocerdo, Oxyrhina, Lamna, Odontaspis, and Notidanus, which are found in
both the Waipara and the Oamaru formations, range through both the cretaceous
and tertiary systems in Europe. Of the remaining three genera, viz. Carcharodon,

* F. Noetling, " Abh. Geol. Specialk. Preussen u. Tbiiring. Staaten," vol. vi., pt. 3, 1885.
Haifisckzahne in " Sitzungsb. Gesells. naturf. Freunde." Berlin. Jahr. 1886, pp. 13-17.

t H. B. Geinitz, " Abb. Gesell. Isis in Dresden," 1883. Koprolitbenlager von Helmstedt, &c,
pp. 3-9, 38-39, 108, 109.

| H. E. Sauvage, " Memoirs Soc. Sci. Nat. Baone et Loire," 1880, pt. 1, pis. i., n. Selacbians from
" Faluns de Bretagne."

§ J. Probst, " Jabresbefte in Wiirtemberg," vols, xxxiii. (1877), p. 69, pis. i., n. Beitrage zur
Kenntniss der fossilen Fiscbe aus der Molasse von Baltringen — continued in vol. xxxiv. (1878), p. Ill,
pi. i. ; and vol. xlii. (1886), p. 301, pi. rx.

|| B. Lawley, Besti fossili della Selacbe trovati a Bicava presso santa luce nelle collem Pisano,
" Atti della Societa Toscano," vol. iv., p. 105. Nuovi denti fossili di Notidanus rinvenato ad Orciano
Pisano, op. cit., p. 196.

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 7

Trygon, and Myliobatis, the two former in Europe do not extend beyond the
tertiary formations, but in New Zealand are found in the Waipara. The last
genus is confined to the Oamaru formations, and has not been found below the
tertiaries in Europe. Species of the genus Sparnodus occur in the chalk as well
as in the tertiaries in Europe, but in New Zealand they are confined to the
Oamaru formation.

A complete list of the fish remains, with the formations from which they have
been obtained, will be found at the close of the description of the species.

In addition to the fish and whale remains there are instances of the occurrence
of teeth of saurians ; they are mostly in a fragmentary condition, and have been
found in several localities on different horizons. The largest tooth was found
by Mr. J. Stephenson at Waitaki ; another, representing only the base, was
discovered by Sir Julius Von Haast in the fine breccia of Amuri Bluff, and a
third in the Amuri Limestone of the Kaikoura peninsula was found by Mr.
H. A. Ingles of Kaikoura.

III.— DESCRIPTION OF THE SPECIES OF FISH-EEMAINS FEOM THE TEETIAEY

FOEMATIONS OF NEW ZEALAND.

Class. — PISCES. Sub-Class I. — PALiEICHTHYES.
Order 1. — Chondkopterygii. Sub-Order 1. — Plagiostomata.
(A)— SELACHOIDEI— SHARKS.
Family I. CARCHARIID-ffi.
Genus. Galeocerdo. Mull, and Henle.

Teeth, flat, triangular, oblique, serrated on both edges, with a deep notch on
the outer margin. Anterior surface arched ; posterior surface hollowed or sloping
backwards. External face flat ; internal rounded. Root not very thick, conform-
ing in outline to base of crown.

Teeth of Galeocerdo are distinguished from those of the genus Galeus, by
having both the anterior and posterior margins denticulated ; in Galeus the anterior
margin is smooth.

The fishes of the genus Galeocerdo first appear in the chalk, they are
found in the tertiary formation, and two species still exist.

8 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

Galeocerdo aculeatus, Davis.
(PL i., figs. 1-3.)

Small, beautifully-preserved teeth, with large central cone, and a lateral
prolongation of the crown on each side, surmounting a widely-expanded base.
The whole of the cutting edge is serrated ; the serrations are larger on the lateral
prolongations than on the sides of the median cone ; the latter, towards the apex, is
nearly smooth. The teeth differ in form, varying, from examples with the width
of the base equal to the height of the crown, to others in which the base is equal
to one and a-half times the height. The external surface of the medianc one is
slightly convex, depressed and flat towards the base ; the summit is pointed and
bent slightly backwards in all the specimens. The internal surface is much more
convex than the external one. The serrations on the lateral margins are irregular,
the largest being in the angle, between the cone and the lateral extensions of the
crown. The root is co-extensive in breadth with the crown, and has a depth equal
to about half the height of the central cone. Externally the surface is concave,
internally it is prominently convex with a median groove extending from the
crown downwards. This species approaches most nearly to those of Galeocerdo
minor, Agass, and Galeocerdo latidens, Agass, " Poissons Fossiles," vol. iii., pp. 231,
232, pi. xxvi. The latter was described by Prof. Agassiz from a specimen in the
Museum at Paris, the origin of which was unknown. G. minor is from the
tertiary of Switzerland, and differs principally in size from G. latidens. The
species now described is readily distinguished by the greater elevation, as compared
with its breadth, of the median cone, and by its being somewhat more erect.

Formation. — Oamaru formation ; Awatere series.

Localities. — Coleridge Gully. Castle Hill Station, Canterbury : Mohaka
Crossing, Napier.

Ex coll. — Canterbury Museum, Christchurch. J. D. Enys, Esq. and Geological
Survey Collections, Wellington.

Family II. LAMNIDiE.

Genus. Carcharodon. Muller and Henle.

Muller and Henle, 1841. " Syst. Beschreib. Plagiostom.," p. 70 (Ex Andrew

Smith, M. S.)

Agassiz, L., . . " Recher. sur les Poiss. Foss.," vol. iii., p. 245.

Teeth very large, compressed, triangular, without basal cavity ; composed of
massive dentine, with reticulated canals ; margin serrated, with or without lateral
cusps.

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 9

Carcharodon angustidens, Agassiz.
(PI. i.j figs. 4-6. PL vi. fig. 22.)

C. angustidens. L. Agassiz, 1833.

„ Pictet, J. F., 1845. .

„ Giebel, C. G., 1848.

„ M'Coy, F.3 1875. .

, , Sauvage, H. E., 1880.

„ Geinitz, H. B., 1883.

„ Noetling, F., 1885. .

" Rech. s. 1. Poiss. Foss.," vol. iii.,
p. 255, pi. xxviii., figs. 20-25,
pi. xxx., fig. 3.

" Traits de Palaeontologie," vol. ii.,
p. 270.

" Fauna der Vorwelt," vol. i., pt. 3.,
p. 350.

" Geol. Surv. of Victoria," Dec. ii.,
p. 8, pi. xi., figs. 2, 3.

" Mem. Soc. Sci. Nat. Saone-et-Loire,"
pt. 1., pi. i.

"Abh. Naturwis. Gesell. Isis., Dres-
den," p. 6, pi. i., fig. 11.

" Abb. Geol. Specialk. Preussen u.
Thuring, Staaten," vol. vi., pt. 3.

Three specimens attributed to this species are represented on Plate i. Whilst
possessing characters which appear to indicate a close relationship, they present
some features which are not identical in each. The teeth are erect, elongate, of
great thickness antero-posteriorly, the lateral margins with the base forming a
more or less acutely-pointed isosceles triangle ; on each side the base of the crown
there is a lateral denticle, the two occupying one-fourth of the total width of the
tooth. The lateral margins are serrated ; the serrations encircle the point as well
as the lateral denticles of the tooth. The external surface between the lateral
margins is convex ; in the direction from the base to the point it is first convex,
but nearer the apex is more or less depressed. The internal surface is highly
convex, almost semicircular. The lateral denticles extend at a right angle from
the margin of the central portion of the tooth. The root or base of the tooth is
large, and extends on each side to a greater width than the base of the crown, from
which it is separated by a line considerably less curved upwards on the external
than on the internal surface. The median portion of the base on the internal
surface is greatly produced, forming a prominent convex bulb, which is adapted
to a corresponding concavity on the external surface of the succeeding tooth. The

TR.VNS. ROY. DUB. SOC, N.S. VOL. IV., PART I. C

10 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

lateral extremities of the base extend downwards, forming bold and firm projections
for the attachment of the tooth in the jaw.

The tooth represented by fig. 4 (PI. i.) is broader and shorter than the others,
and has probably been located in the posterior part of the jaws. It is the most
perfect specimen included in the series. The median length of the external face
is 1*6 inch, the breadth between the extremities of the two lateral denticles is 1*9
inch ; the base is 2*1 inches broad, and its depth 0*6 inch; its diameter, between
the internal and external surfaces, is greatest in a line through the central convex
bulb, named above, is 0*7 inch.

Fig. 5 represents a tooth from the anterior portion of the lower jaw; its form
is considerably more lanceolate than that of fig. 4. Its median length is 2'0 inches
from the apex of the line dividing the crown from the base to the point. One of
the extremities of the base is wanting, but from the median line to the extremity
of the remaining one is 0'85 inch, or for the breadth of the whole tooth 1-7 inch.
The lateral extremities of the root are elongated correspondingly with the crown.
The third example (fig. 6) is probably from the upper jaw, it is broader in propor-
tion to the length than the teeth from the lower jaws, this being more especially
noted near the point of the tooth. The lateral denticles are broken off, and a
portion of the base has disappeared, so that its exact proportions as compared with
the others cannot be recorded.

This species approaches most nearly to those figured by Agassiz, under the
name of Carcharodon auricidatas, DeBl., " Eech. sur les Poiss. Foss.," vol. iii., p.
254, pi. xxviii., figs. 17-19, Carcharodon angustidens, Agass., op. cit., vol. iii.,
p. 255, pi. xxviii., figs. 20-25, and pi. xxx., fig. 3, the latter with the name C.
lanceolatus. Prof. Agassiz described the species from specimens existing in the
Museum at Paris, Strasburg, and elsewhere, of which the original locality was
unknown; but specimens have been discovered in the Tertiary strata at Kressenberg
and Dax. The species now described differs from C. auriculatus in its robust
proportions. The latter is described as comparatively thin, the external face
being flat. It differs from the type figured by Agassiz as C. angustidens, by the
great prominence of the median bulb of the root and the corresponding concavity
of the opposite surface. The enamelled surface of the crown in Agassiz's specimens
is divided from the root almost in a straight line, whilst in the New Zealand
specimens the division extends high on the median portion of the tooth forming a
deeply concave line ; the lateral denticles, as compared with the median extent of
the coronal surface, are situated at a much lower level in tins than in the species
described by Agassiz. Notwithstanding these variations in the form of the teeth,
they do not appear to be of such a character as to render doubtful the position in
which the teeth now described should be located, and they are included with the
specimens described by Agassiz in the species C. angustidens without hesitation.
Professor M'Coy has assented to the inclusion by Dr. Gibbes (" Monog. Squal.") of

Davis — On Fossil-Fish Picmains from the Tertiary Formations of New Zealand. 11

the following species with that of Carcharodon angustidens, viz. : C. lanceolatus,
C. auriculatus, C. megalotus, C. turgidus, C. heterodon, C. scmiserratas, and C.
toliapicus. Several of these were described by Agassiz from specimens of which
the history was not known, localities were only surmised at, and it is possible that
some, or even all, may pertain to one species ; but without examination of all the
types, and comparison with other specimens which may have been discovered
during the fifty years which have elapsed since the publication of the "Poissons
Fossiles," considerable caution should be exercised in accepting the determination
of Dr. Gibbes.

In the collections sent by Sir J. Hector, Director-General of the Geological
Survey, there is a beautiful little tooth in such an exquisitely perfect state of
preservation, that it seems impossible that it can have been used. It is triangular
in outline, the margins are minutely serrated, the point perfect. There is a lateral
cusp presenting a rounded outline, and apparently not fully developed. The root
is divided and deep, but narrower than the base of the crown. The form and
characters of the tooth appear to indicate an immature example of Carcharodon
angustidens, and it appears desirable to associate it with this species, at any rate
provisionally. It is represented on Plate vi., fig. 22.

The teeth of Carcharodon angustidens have a world-wide distribution in Tertiary
strata. In England they are found in the London clay, and in the island of
Sheppey ; at Antwerp, in Belgium ; at Kressenberg, Dax, Helmstadt, and other
places in Germany. In Westphalia numerous specimens are obtained from the
Miocene Tertiary strata at Biinde. The teeth occur in the Tertiary strata of North
America, and Prof. F. M'Coy has found and described examples from the Miocene
sands of Bird Rock, near Geelong, in Victoria, Australia. This species and the
one next following are, perhaps, the most abundant and widely distributed of all
the sharks in the Tertiary strata, especially of Miocene age. The genus is
represented by only one living species at the present time. The teeth of Carcha-
rodon may be readily distinguished from those of Carcharias by the absence of the
conical cavity in the base.

Formation. — Oamaru formation, and Waireka series.

Localities. — Waihoa Falls; Wekapass; Curiosity Shop; Deep Creek, Blueskin;
Amuri limestone, Kaikoura Peninsula ; Greymarls, Wekapass stone ; Kakahu, near
Canterbury (lower coal-beds) ; Waitaki Valley (Maraewhenna limestone) ; Raglan,
Auckland ; Amuri Bluff ; Waihola Gorge ; Castle Hill Station, near Canterbury ;
Esk River, Hawkes Bay.

Fx coll. — Canterbury and Otago Museums; J. D. Enys, Esq., and Geological
Survey Collections, Wellington.

C 2

12 Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand.

Carcharias megalodon,

5>

Car char odon megalodon, Agassiz

(PL ir., figs. 1-3.)
L. Agassiz, 1833-13,

Agassiz, .

" Rech. s. 1. Poiss. Foss.," vol. iii.,

p. 247, pL xxix.
" Egerton's Catalogue."

macro don, .
grosseserratus,
megalodon,

1834,
James, 1836,

1837,

Brown, H. G.,

)5
J 1

J)

5)

1835,
1837,
1839,

Philippi, .

Carcliarodon megalodon. Geinitz, H. B., 1843,

Miinster Graf., 1841,

" Verhandl. Bohm Museum," p. 60.
" Edin. New Phil. Jour.," vol. xxi.,
p. 319.

"Loud. Mag. Nat. Hist,," vol. i.,

p. 225, fig. 24.
"Leth geogn.," vol. ii., p. 1163,

pi. xliii., fig. 1.
" Jahrb. des Petref .," p. 740.

„ pp. 494, 123.
„ p. 114.
" Tertiarversteinerg," p. 20.
" Versteingk,"p.l72,pl.vn.,fig.l7.
" Beitrage zm' Petref act," vol.

vii., p. 22.
"Traits de Paleeont," vol. ii.,
p. 270.

" Fauna d.Vorwelt," vol. ii., pt. 3,
p. 348.

" Geol. Surv. Victoria," Dec. ii.,

p. 9, pi. xi., fig. 4.
"Mem. Soc. Sci. Nat. Saone-et-
Loire," p. 1, pi. i.

Teeth very large, un symmetrical, broader than long, triangular, without
lateral cusps, cutting edges finely serrated. External surface flat or slightly
concave. Internal surface convex. Upper portion of crown inclined outwardly.
Line dividing the crown from the base deeply arched, especially on the internal
surface. The height of the crown is 2*0 inches ; right lateral margin 3'4 inches;
opposite one an inch shorter. Outline of margins sigmoidal. Root same breadth
as base of crown, has a depth of 0-9 inch. It is thicker than the crown, concave
on the outside, and on the inner one convex. The base of the root is deeply
concave, parallel with the external base of the crown.

Pictet, J. F., 1845, .
Giebel, C. G., 1848, .
M'Coy, F., 1875, .
Sauvage, H. E., 1880,

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neto Zealand. 13

The teeth represented by figs. 1—3 on PI. n. are the only ones included in the
collections placed in my charge. Fig. 2 (PL u.) represents an unsymmetrical form
which may be probably accounted for by the posterior position it has occupied in the
jaw of the fish. The absence of lateral denticles dissociates them from Carcharodon
angustidens and from C. robustus ; they are distinguished by the thick prominent
base of the latter, by the height of the crown in proportion to its breadth, and the
concave curvature of the lateral margins which in the species now described are
sigmoidal. They may further be distinguished from C. angustidens by their
greater breadth in proportion to the height of the crown ; it is thinner, the surface
much less lustrous, and the marginal serrations less deeply indented.

Carcharodon megalodon, the largest of the Tertiary elasmobranchs, has an
extremely wide geographical range. It has been found in the English, German,
Swiss, Maltese, and Italian Tertiary strata. It is recorded from several American
localities, and has been discovered in the Victorian Tertiary deposits near Geelong,
in Australia. Its range is now extended by its discovery at Wekapass to New
Zealand. Large teeth of this species, quite equal in size to any found fossil, were
dredged by the Challenger expedition in the deep waters of the Atlantic and Pacific
seas — a circumstance which indicates that this greatest of sharks existed until
recent times in considerable numbers, and has become extinct within almost the
historic period.

Formation and Locality. — Oamaru formation ; Waireka series ; WekajDass ; Cape
Foulwind ; Nelson ; near Cobley's Creek.

Ex coll. — Canterbury Museum, Christchurch ; Geological Survey Collections,
Wellington.

Carcharodon robustus, Davis.
(PL i.j fig. 7.)

Teeth large, equilateral, erect, lateral denticles absent. Lateral margins finely
serrated. The height is 2*1 inches from the central apex of the line dividing the
crown from the base and the point of the tooth, and its breadth across the base is
about 2*3 inches. The length of each lateral margin is 2*8 inches, making
allowance for a small part of the base which is broken off. The external surface
of the crown is almost flat, a slight convexity arising on each side the median line
near the basal extremity. The internal surface is laterally convex, tapering
towards the point. The line dividing the crown from the base is somewhat
obtusely convex on the external surface, that on the opposite one being more
acute, the two sides forming a right angle. The root is large and thick, open and
porous in structure. It was probably 2*4 inches in breadth. Its surface recedes

14 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

from the front of the tooth, and extends in a well-rounded and prominent extension
behind. The median portion is devoid of the prominent and well-defined projec-
tion of Carcharodon angustidens, Ag., and its lateral expansions are smaller and
less prominent. On the other hand, the root of this species is deeper and more
bulky in the median portion, thinning out towards each side. The under surface
is moderately concave, whilst that of C. angustidens is deeply so. The crown of
the two sj)ecies may be readily distinguished by the difference in form ; that of
C. angustidens elongated, its lateral margins convex, with a lateral denticle on each
side, and the external surface of the crown slightly convex ; in this species the
external surface is flat, the base is much wider and without denticles, and the
lateral margins are decidedly concave.

Amongst European species to which this one appears to be most nearly related
are the two species, Carcharodon subauricidatus, Agass., " Poissons Fossiles," vol. iii.,
]). 251, pi. xxxa., figs. 11-13, and C. megalodon, Agass., op. cit., p. 247, pi. xxviii.
The former may be distinguished by its greater breadth across the base of the
crown and the more or less convex outline of the lateral margins. Its root is com-
paratively thin; and the tooth altogether less robust than the one now described.
The same features which serve to discriminate this species from C. subauricidatus,
viz. the thick and massive root, and the concave outline of the serrated edges, also
distinguish it from C. megalodon. A doubt is expressed by Prof. Agassiz as to
whether the two species, C. megalodon and subauricidatus, may not be the same.
The former was described from specimens found in the Museum of Stuttgart, but
the locality from which they were obtained was not known, others in the Museum
at Paris were also without locality. It is not improbable that they may be
varieties of one species along with, and including, that described by Agassiz as
Carcharodon rectidens, " Rech. sur les Poissons Fossiles," vol iii., p. 250, pi. xxxa.,
fig. 10," in which case they would all be included in the species C. megalodon, Ag.

Formation and Locality. — Oamaru formation, Waitaki.
Ex coll. — A. M'Kay, Otago, New Zealand.

Genus. Otodus. Agassiz.

Agassiz, L. " Rech. sur les Poissons Fossiles," vol. iii., p. 266.

This genus is defined as occupying an intermediate position between Carcha-
rodon and Oxyrhina or Lamna. It differs from Carcharodon in the complete
absence of marginal serrations. It may be distinguished from Oxyrhina by the
presence of a well-developed lateral denticle on each side the median cone. The
lateral denticles are oftener rounded than compressed or sharp. The median
cone is similar in form to the cone of Oxyrhina. In Lamna and Odontaspis the

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 15

lateral denticles or cones are smaller, more cylindrical and pointed, and the teeth
generally more elongated : in Otodus they are broad. The root is largely
developed and thick, but is devoid of the deep, lateral prolongations which
distinguishes Lamna.

Otodus obliquus, Agassiz.

O. obliquus. Agassiz, L. " Rech. s. 1. Poiss. Foss.," vol. iii., p. 267, Pis. xxxi.

and xxxvi., figs. 22—27.

(PI. vii., fig 16.)

A large tooth, well worn and rounded, apparently by attrition after fossiliza-
tion, from the Amuri series of Amuri Bluff, appears to belong to this genus. The
median cone is 0-8 inch across the base, and 0*7 inch in height. The upper part
is much worn and very obtuse ; the surface is smooth ; on one side a small,
rounded, lateral cone is preserved ; the opposite one is broken away. The root is
large and well rounded on the posterior surface ; the margin of the under surface
is concave ; its lateral prolongations extending beyond the base of the crown.
It is imperfect, and the exact dimensions cannot be given. It possesses many of
the characters of Otodus obliquus, Agassiz, from the London clay, and is provi-
sionally included in that species.

Formation. — Amuri series, Lower Greensand.

Locality. — West Wing, Amuri Bluff.

Ex coll. — Sir J. Hector, Colonial Museum, Wellington.

Genus. Lamna. Cuvieb.
Agassiz, L. " Rech. sur les Poissons Fossiles," vol. iii., p. 287.

Teeth medium size ; elongated ; narrow in proportion to the height ; sharply-
pointed ; cutting edge smooth ; base expanded ; lateral denticles present ; root
large, and deeply bifurcated.

The teeth of Lamna may be distinguished from those of Otodus by being
rounder and less compressed, and having the lateral cones smaller and pointed.
Oxyrhina is devoid of lateral denticles, and is thinner and more triangular in
outline than Lamna. This genus first appears in the Chalk formation, and is
still existing.

Lamna huttoni, Davis.

(PL in., figs. 1 a, b, c.)

Teeth long, slender, curved, and pointed. The length of the crown 1-6
inches on the external surface. The base is 0*4 inch in diameter between the two

16 Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand.

lateral margins; midway from the base to the apex the crown is 0'3 inch across,
and thence it gradually tapers to the apex. The external surface is slightly
convex near the base, much less so towards the apex ; a groove runs along each
margin, which, together with a similar one on the internal surface, causes the
lateral margins to assume a sharp, cutting edge, which is continued towards and
surrounds the point of the tooth. The internal surface is prominently convex
from the base to the point. The basal portion of the crown is much exjmnded
internally and externally, and there are indications of a somewhat massive root,
but unfortunately this portion of the tooth is not perfect in any of the sjDecimens.
Secondary denticles, if they have been present, are not preserved. The line
dividing the enamelled surface from the root is higher on the internal than on the
external surface. The tooth is curved sigmoidally. (PI. ill., fig. lc.) A series
of minute striae extend vertically from the base towards the point on the internal
surface ; the striae disappear before reaching the lateral margins, leaving along
each a smooth space. The external surface is entirely smooth. Examples of the
teeth exhibit a peculiar twist or contortion of the crown, not shared by the
majority, which is probably due to the position which the tooth occupied in the
mouth.

This species appears to be somewhat nearly related to Lamna elegans, Agass.
(" Poiss. Fossiles," vol. iii., p. 289, pi. xxxv., figs. 1—7, and pi. xxxvua, figs. 58,
59), from the London clay, and the Calcaire grossier near Paris. L. elegans is
slender, regular, and erect, having a considerable thickness near the root, and
tapering towards the point ; it possesses a small lateral denticle on each side the
median cone, and its margins are sharp ; this species may be distinguished from
Lamna elegans by its elongated and less triangular form, greater curvature, and
its slightly contorted or twisted outline.

A number of specimens of this species occur in the Curiosity Shop beds horizon
at Gorge Hill, Pareora. They are the lowest beds of the Oamaru formation. The
teeth are preserved in a peculiar manner. The outside enamelled shell of the
tooth remains intact, whilst the whole of the interior structure is gone, leaving
simply a hollow cube. They are very fragile.

I have taken the liberty to designate this species by the name of Prof. F. W.
Hutton, to whose initiative I am indebted for the opportunity to arrange and
describe the fossils here enumerated.

Formation. — Oamaru system and Waireka series.

Localities. — Marnawhenna ; Otago ; Awamoko ; Amuri Bluff j Cave Valley,
Oamaru ; Gorge Hill, Pareora.

Ex coll. — Messrs. J. D. Enys, B. Gillies, and Ashcroft; Canterbury Museum.
Geological Survey Collections, "Wellington.

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand. 17

Lamna incurva, Davis.
(PI. in., figs. 2-5.)

The teeth of this species differ from those of Lamna huttoni in their greater
acuteness, rounded form, and the almost total absence of lateral cutting edges.
The average length is 0-8 inch, the base of the crown 0-2 inch across, whence
it gradually decreases to the point. The external surface is slightly convex
throughout its length ; it is perfectly smooth. The internal surface is deeply
convex and also smooth : in this respect differing from L. huttoni, which is
striated on the internal surface. The diameter of the tooth between the external
and internal surfaces is little less than the lateral one, in this respect also differing
from L. huttoni, in which the relative diameters are as two to one. The teeth are
curved considerably inwards from the base of the crown nearly to the apex, the
latter having a slight inclination forwards. Lateral denticles absent. Base of the
crown straight across the external surface ; on the internal one it is arched
upwards to a considerable extent.

The roots in the specimens now described from Coleridge Gully and Curiosity
Shop are very imperfectly preserved. A specimen collected by H. A. Ingles,
Esq., from the Amuri Limestone of the Kaikoura Peninsula, exhibits the root in
a good state of preservation. It retreats from the external surface of the crown,
leaving a deep concavity ; two prongs descend from the lateral extremities to a
considerable depth. The internal projection is large and prominent, forming a
somewhat angular bulb, from which the surface retreats on each side to the lateral
prongs (PI. in., fig. 2 a).

A small specimen is represented on PI. in., fig. 5. Compared with the others
it is short and thick.

The teeth occupying the anterior position in the jaws are broader, slightly
larger, and much less curved than those situated posteriorly ; they are elliptical in
section, as compared with the others, which are nearly circular. A large number
of specimens of this species have been found. They vary much in size; the largest, a
posterior tooth from the Curiosity Shop beds, is 1*1 inch in length. It is partially
embedded in a matrix of brownish, shelly limestone. Others are less than one-third
that size. The smaller ones, however, possess all the characters identifying the
larger, and there can be little doubt that they are young examples of the same species.

Several small specimens of this species have been found in the beds at Gorge
Hill, Pareora. They are preserved in a similar manner to L. huttoni, already
described, from the same locality.

Formation. — Oamaru and Waipara systems; Waireka series ; Cretaceo-Tertiaries.
Localities. — Broken Eiver ; Curiosity Shop ; Coleridge Gully ; Amuri Lime-
stone ; Kaikoura Peninsula ; Gorge Hill, Pareora ; Waitako Valley ; Tata Island

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART I. D

18 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

Limestone, Nelson ; Trelissic, Canterbury ; Mercer, Waikato River, Auckland ;
White Rock, Malvern Hills ; "Waihola series, Otago.

Ex coll. — Canterbury and Otago Museums ; Geological Survey Collections,
Wellington. H. J. Ingles, Esq.

Lamna ensicalata, Davis.
(PI. in., figs. 6, 7.)

A few examples of this species have been found in the Oamaru formation or
Lower Miocene of Prof. Hutton, at Oamaru. The tooth most perfectly preserved
and selected as the type is 0*65 inch in height ; the margins are equilateral, 0*8
inch in length ; the base of the crown bifurcates laterally into two forks, the
extremities of which are 0*5 inch across; the crown is 0'2 inch across the external
face, converging towards the apex, and ending in an obtuse point. The tooth is
strong, erect, the slightly convex inclination of the external aspect being balanced
by that of the internal surface. The external surface is moderately convex, its
lateral margins forming a nearly rectangular junction with those of the deeply
convex internal surface. At a distance of 0*5 inch from the apex the crown
suddenly expands laterally and bifurcates, the commencement of the expansion
being marked by a peculiar constriction of the surface. The bifurcation extends
over the lateral forks of the root. The root is more widely expanded than the
base of the crown, and descends in lateral prongs, with a wide and highly concave
space between. The central portion of the root forms internally a prominent
bulb, whilst the external base of the crown is free ; the lateral prongs extend
outwards from the internal median prominence with a bold curve, ending more or
less acutely. They are thick and strong. A faint indication of lateral denticles
exists on each side of the base of the crown.

This species is readily distinguished from any others from the New Zealand
strata by the, at first constricted, and then widely-expanded base, and the
straight, thick, obtusely-pointed crown. In the latter respect Lamna huttoni,
approaches nearest, but its striated internal surface and curved aspect distinguish it.
Amongst European species Lamna cuspidata, Agassiz (" Poissons Fossiles," vol. iii.,
p. 290, pi. xxxvu. a, figs. 43-50), from the Tertiary beds of Switzerland, is probably
most nearly related. It is similarly erect, smooth on each surface, and thick. Its
root is large and widely bifurcated. The characters of the base of the crown, given
above, and the absence of well-defined lateral denticles, which are conspicuous in
well-preserved specimens of L. cuspidata, Ag., separate this species from the Swiss one.

Formation. — Oamaru formation.
Locality. — Oamaru.

Ex coll. — Canterbury Museum, Christchurch, New Zealand,

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neio Zealand. 19

Lamna marginalis, Davis.
(PL m., figs. 8-10.)

The specimens comprised in this species are in some respects much -like
examples of the genus Oxyrhina. The crown is thin and flat, wide at the base,
diminishing to a point. The presence of a small lateral denticle, however,
indicates most clearly its relationship with the genus Lamna. The height of the
crown is 0*6 inch, width across the base of the median cone 0'3 inch, to which
must be added 0*05 inch on each side, to include the lateral denticle. The
external surface is flat or slightly convex and smooth, rising in a straight line from
the base to the apex. The internal surface is convex ; from the base of the enamel
a number of minute striae ascend the crown to a distance of one-third its height,
gradually disappearing. The margins are very thin and knife-like. The line
dividing the crown from the root on the external surface is straight; on the
internal surface a little concave. The lateral denticles are small, rather rounded
than pointed. The root is large and widely expanded, retreating from the median
external surface with a moderate concavity and a corresponding convexity on the
internal one ; the root descends on each side diagonally, the terminations being
separated by a distance of 0'7 inch — double the width of the base of the crown.
The prongs are thin and aliform ; the median teeth are straight, with equilateral
margins, the internal surface presents greater convexity, and consequently they
are thicker than the teeth derived from the posterior parts of the jaws. The latter
are more or less arched backwards.

This species is easily recognised amongst other New Zealand forms by its
thinness, especially at the lateral margins, hence its specific name, by the obtuse
lateral denticles and the great lateral expansion of its root.

Formation. — Oamaru and Waipara formations ; Cretaceo-Tertiary.

Localities. — Broken Biver ; Amuri Limestone ; Kaikoura Peninsula ; Totora
Limestone, Mokau Valley ; Nummulite Beds, Wharaema ; Calcareous Greensand,
Wekapass ; Teredo Limestone, East Wing, Amuri Bluff.

Ex coll. — Otago Museum ; Canterbury Museum, Christchurch ; Geological
Survey Collections, "Wellington.

Lamna attenuata, Davis.
(PI. in., fig. 11.)

Small teeth, 0-25 inch in length, 0*1 inch across the base ; base rapidly becomes
accuminate, and the central cone ascends in a fine shaft, with a finely pointed apex.
External surface rounded and curved inwards. Internal surface still more convex,

D2

20 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

expanding at the base with a concave outline dividing it from the root ; lateral
margins scarcely perceptible. A minute lateral denticle arises on each margin.
The root is absent. This small tooth is characterized by the extreme tenuity of
its form and the roundness of the cone.

Formation. — Oam aru formation.
Locality. — Coleridge Gully.

Ex coll. — Canterbury Museum, Christchurch, New Zealand.

Lamna lanceolata, Davis.
(PI. in., figs. 12 a, b, e, d.)

The teeth of this species have been obtained from several localities of the
Oamaru formation. They are of peculiar lanceolate form, erect, slender, and
generally well worn and rounded at the apex. The teeth are firmly attached to
a large and clavate root. The crown is 06 inch in length, and to this must be
added 0-25 inch, the depth of the root. Except in rare instances the root is
detached, fortunately one or two specimens are perfect. A number of the
specimens are curved backwards, due probably to their occupation of a position
on the posterior part of the jaws. The external surface is slightly convex near the
base ; higher it is plane in the centre, slightly depressed on each side towards the
margins, which are thin but rounded. The width of the tooth is 0*15 inch,
gradually tapering near the apex. The internal surface of the crown is very
slightly more convex near the base; its upper part is depressed in a similar manner
to that of the external surface. The base of the crown is expanded, and contrary
to the ordinary rule in this genus the outline is more or less convex on each side.
The surface of the crown is quite smooth. The posteriorly curved teeth are some-
what more slender than the erect anterior ones, and the lateral margins begin to
converge towards the apex, at a point nearer the base. The root is very large and
thick ; from the base of the crown it expands rapidly, especially in the posterior
direction ; its inferior antero-posterior diameter attains 0'45 inch, laterally it is
0*25 inch. In form it resembles a clubfoot twisted backwards. Its under surface
is hollow (fig. 12 d).

This species is included in the genus Lamna with some little doubt. The
long, thin, slender crown, and the thick, solid, nonbifurcating root do not conform
with the characters of the genus, except in a superficial manner; there are no
lateral denticles ; in the latter respect it agrees with Oxyrhina, but it cannot be
considered as a species of that genus.

Formation — Oamaru formation.

Localities. — Castle Hill Station, Canterbury ; Broken River, Coleridge Gully.
Ex coll. — John Davies Enys, Esq., Cambridge Museum, Christchurch.

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 21

Lamna carinata, Davis.
(PI. in., fig. 13.)

This species is closely allied to the last described (L. lanceolata, Davis); it differs
in being curved inwards, instead of straight towards the point ; it is thicker, with
angular lateral margins, and a median carina along the external surface. From the
latter feature the species derives its specific appellation. The tooth is 0*5 inch in
length; the root is not preserved. The external surface is 0*1 inch in breadth; it
is plain, excepting a keel, which runs up the centre from the base to the apex; the
lateral margins are slightly produced and form an angular and sharp edge. The
internal surface is convex, and vertical striae extend from the base nearly to the
apex. The tooth bends gently inwards. The line dividing the crown from the
root appears to have been straight. The root is absent.

Formation. — Waipara formation .

Locality. — Amuri Limestone ; Kaikoura Peninsula, Kaikoura, New Zealand.
Ex coll. — H. J. Ingles, Esq., Otago Museum.

Lamna sp. (?) Vertebra?.
(PI. in., figs. 14, 15.)

Several vertebrae have been discovered in the strata of the Oamaru formation.
They vary in size, and may not all belong to the same species of shark. The
specimen represented on PI. in., fig. 14, is the vertebra of a Lamna. It is deeply
biconcave ; the periphery is constituted of a number of columns separated by large
interspaces, which have afforded space for the insertion of the cartilages support-
ing the apophysis. The external diameter of the centrum is 1*3 inch, and the
height of the periphery 0*6 inch.

A second specimen represented by fig. 15 is much smaller. It is similarly
biconcave, but the divisions of the periphery are less numerous, and it has a more
dense and stronger appearance than the larger specimen.

Formation and locality. — Oamaru formation. (14) Awamoke. (15) Kaikoura.
Ex coll.— (14) R. Gillies, Esq. (Prof. Hutton). (15) T. J. Parker, Esq.,
Otago Museum.

Lamna hectori, Davis.
(PI. in., fig. 16.)

Teeth medium size, robust, equilateral, expanded near the base, with a minute
denticle on each side. External surface only visible, the internal one embedded

22 Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand.

in the matrix. Median length of the crown 0*4 inch ; on each side, to the extremity
of the root, it is 0*6 inch; breadth across the base 0 3 inch, higher the base is
speedily reduced to one-half that diameter, and thus diminishes to a somewhat
obtuse point. The external surface of the crown is depressed, with the exception
of a broad median ridge, extending from the base half-way up the tooth. The
margins are slightly produced, but not acutely, as in Lamna marginalia, Davis.
Near the base they become somewhat bulbous and expanded, and an indentation
separates the base of the margin from a small lateral denticle on each side. The
surface is smooth, without striations. The root is short, width the same as the
base of the tooth. The lateral portions extend one-tenth of an inch ; the median
area is depressed deeply, lobate and concave. The internal surface is hidden in
the matrix. It is proposed to distinguish this species by the name of its discoverer,
Sir James Hector.

Formation, — Amuri series.

Locality. — West Wing, Amuri Bluff.

Ex coll. — Sir J. Hector, Geological Survey of New Zealand.

Genus. Odontaspis. M. & H.

Odontaspis. Muller and Henle. " Systematische Beschreibung der

Plagiostomen," p. 73.

Teeth medium size, long, tapering, acuminate, cutting edges smooth, base
widely expanded, lateral cones variable in number, larger, and sharper-pointed
than those of Lamna.

Odontaspis is regarded by MM. Muller and Henle as a distinct and well-
defined genus, and Dr. G until er regards it from a similar point of view. Prof.
Agassiz (" Poiss. Foss.," vol. iii., p. 287) was of opinion that its characteristics are
not of sufficient importance to necessitate a separate genus, and he describes a
number of species of the type of Odontaspis as a sub-genus or variety of Lamna.
The remains of the genus Odontaspis first appear like that of Lamna in the chalk
formation, and the genus attained its greatest abundance during the Tertiary
period. It still survives in the seas of the present day.

Odontaspis acuta, Davis.
(PI. v., figs. 1, 2.)

The teeth on which this species is based are amongst the most rare forms
derived from the Oamaru formation, they are found in the Curiosity Shop beds
and at Trelissic, Canterbury. The teeth are of moderate size, slightly curved

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neio Zealand. 23

outwards, graceful in outline, sharply-pointed, broad at the base, arising from
which, in addition to the large central cone, are two or three small lateral denticles
on each side, diminishing in size as they recede from the centre. The external
surface of the median cone is depressed at the base, the latter having a slightly
concave margin where attached to the root. The higher surface of the cone is
convex, and towards the point slightly recurved ; the median height is 0*7 inch.
The first small denticles rise from the base to a height of 0*1 inch ; they are sharply-
pointed and curve inwards towards the central cone. Beyond these the second and
third denticles are similar in form, but less in size. The base of the crown is 0*5
inch in breadth. The internal surface is only partially exposed, the basal portion
of the tooth lies hidden in matrix ; the upper part is convex, slightly more so than
that of the external surface. The lateral margins are produced, and moderately
thin and sharp, a character shared by those of the lateral denticles. The root is
deeply concave on the anterior surface and correspondingly prominent behind ;
it extends laterally to a considerably greater width than the base of the crown.
(See fig. 2a.)

This species differs from others from the strata of New Zealand, in the peculiar
form and arrangement of the denticles. Other species of the same genus occur,
but they are easily distinguished by the shortness of the median cone in propor-
tion to the breadth of the base. Of European species they most nearly resemble
Odontaspis acutissima, Agassiz. (" Poissons Fossiles," vol. iii., p. 294, pi. xxxvua.,
figs. 33, 34.) It is described as very sharp, with one long lateral denticle, equally
sharp on each side ; the internal face is striated. The locality from which the
type was obtained is not known, but a second specimen was found in the Tertiary
strata of Berthond, in Switzerland. This species differs in the length, and less
acuminate form of the central cone, and in the presence of three lateral cones
instead of one. The latter feature also distinguishes this species from that of
0. subulata, (op. cit., p. 296, pi. xxxvn a., figs. 5, 7), from the chalk and greensand,
which closely resembles 0. acutissima, Agassiz, in its form.

Formation. — Oamaru system.

Locality. — Curiosity Shop beds, and Trelissic, Canterbury.
Ex coll. — Canterbury Museum, Christchurch, New Zealand ; Geological Survey
Collections, Wellington.

Odontaspis exigua, Davis.

(PI. v., figs.^3, 4, 5.)

Teeth small, middle cusp acutely angular and inclined posteriorly, with two
smaller cusps on each side, the outer ones smallest. The outer surface nearly flat
at the base, slightly convex above ; inner surface strongly convex ; cutting edges
fine and smooth, points acuminate. Ganoine of surface strong and glistening,

24 Davis — On Fossil- Fish Remains from the Tertiary Formations of New Zealand.

smooth on the outer surface, with slight striations on the inner; most clearly
marked near the base. Line dividing crown from root straight on both sides.
Root more widely expanded than the base of crown, convex on the outside, deeply
concave on the inner one, with lateral extremities boldly prominent, and more or
less pointed. Height of median cone 03, breadth of base 0*35 inch, of which the
median cone occupies 0*2 inch. Root O'l inch in depth, greatest width 0'4 inch.
This tooth (fig. 3) probably occupied a position midway between the anterior and
posterior extremities of the jaw. Others occur of similar form but smaller, and
others again, which appear to have belonged to the same species (fig. 5) are more
elongated in proportion to the breadth, finely pointed and possessing only one
denticle on each side the principal cone. The latter were probably located in the
front of the jaw. The small tooth (fig. 4) has the characteristics of one of the
small posterior teeth almost equally divided into three cones, the two lateral ones
being quite half the size of the median one in this specimen. The tooth is 0'15
inch in breadth, and the height, including the root, is about the same.

This species differs from 0. acuta in having a broadly expanded base, the
cones being more triangular and flatter, those of 0. acuta are recurved more or
less sigmoidally, whilst in this species they are straight.

Formation. — Oamaru formation.

Locality. — Broken River. Castle Hill Station, near Canterbury ; Coleridge,
Trelissic.

Ex coll. — J. D. Enys, Esq., Canterbury Museum, Christchurch ; Geological
Survey Collections, Wellington.

Odontaspis kaikoraensis, Davis.
(PI. v., figs. 6-10.)

Teeth very broad, with thick base, from which ascends a median cone ; and on
each side, separated by a wide interval, is at least one lateral denticle. The base
of the tooth is 0*5 inch across ; and the height of the median cone, including the
base, is 0-55 inch ; of this the base takes 0-2 inch. Median cone is erect, tapering,
slightly curved outwards ; lateral margins produced and sharp ; internal surface
convex, extern alone flat ; the surface is enamelled and smooth, the apex pointed ;
the lateral denticles are broad at the base, short, obtusely pointed, separated by
their own diameter from the central cone ; the base is externally concave,
prominent on each side ; the internal surface is produced below the median cone,
retreating on each side ; the inferior surface is concave.

This species differs from any other previously described from New Zealand in
the great width of the base, as compared with the diameter of the denticles and in

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand. 25

the open space between the central cone and the lateral cones. The central
cone is slender and somewhat cylindrical — a feature which appears to indicate its
generic relationship with either Lamna or Odontaspis, whilst distinguishing it
from Otodus, the median cone of which is broad and compressed. The imperfec-
tion of one of the lateral extremities renders the number of lateral denticles
uncertain; and the distinction made by Prof. Agassiz (u Poiss. Foss.," vol. iii.,
p. 287) between Lamna, with not more than one denticle on each side, and
Odontaspis, with a variable number, cannot be readily made out ; but other
specimens from the same locality, though not so perfect in other respects, have
two lateral denticles on one side the median cone, if not on both.

Formation and Locality. — Waipara system ; Kaikoura ; Amuri Bluff.
Ex coll. — Sir Julius von Haast; J. Davies Enys, Esq.; Geological Survey
Collection, Wellington.

Odontaspis sulcata, Davis.

(PI. v., figs. 11, 12, 13.)

Teeth, with large base, 0*5 to 0-8 of an inch in extent ; the central cone rises
to a height slighly less than half the breadth of the base ; in a tooth 0"6 across
the base, the height of the cone is 0*25 inch, and its width 015 inch ; on each side
the median cone are two or three lateral cones, diminishing in size as they recede
from the centre. All the cones are deeply grooved at the base ; the grooves
disappear midway up the surface. The upper part is smooth ; the lateral margins
are smooth, and, where unworn, form a sharp cutting-edge. The base is 0*1 inch
in depth, anteriorly concave and somewhat retreating, posteriorly more or less
produced.

This species may be distinguished from those already described by the large
expansion of the base, and the proportionate width of the lateral cones. The
deeply-sulcated character of the lower portion of the several cones is not found in
other species from New Zealand.

Formation. — Black Grit series.

Locality. — East Wing, Amuri Bluff.

Ex coll. — Sir J. Hector, Colonial Museum, Wellington.

TRANS. ROY. DUB. SOU., N.S. VOL. IV., PART I. E

26 Davis — On Fossil- Fish Remains from the Tertiary Formations of New Zealand.

Genus. Oxyrhina. Agassiz.
Oxyrhina. Agassiz, L. " Rech. sur les Poissons Fossiles." vol. iii., p. 276.

Teeth medium size, acutely triangular, compressed, slender, margins smooth,
acute point, without lateral denticles or cusps.

Prof. Agasssiz regarded Oxyrhina as closely related to the genus Lamna, but
distinguished by its slender and flat or compressed form, the true Lamna being-
thicker, straighter, and not so broad. It is also devoid of lateral denticles, which
Lamna possesses. The genus Otodus is broader, less compressed, and more
triangular in outline. It is also possessed of lateral denticles.

The genus Oxyrhina is found in the chalk, but is most abundant in the
Tertiary formations.

Oxyrhina von haastii, Davis.
(PI. iv., figs. 1-3.)

This species occurs in considerable numbers in the Lower Limestone at
Oamaru. The teeth average an inch in length, broad at the base, they gradually
taper to an acutely-pointed apex. The lateral margins are devoid of serrations,
and form a sharp cutting-edge. The external surface is more or less flat,
slightly concave near the base. The enamel is grooved at the base, the slight
channels so formed disappearing on the surface towards the apex. The point is
curved outwards. The internal surface is deeply convex, expanding widely at
the base to envelop a largely expanded root, and bending sigmoidally upwards
towards the recurved apex. The base of the enamel forms a slight concavity on
the external surface, the concave outline being considerably emphasized on the
internal one.

A mass of limestone with about twenty teeth attached is included in the
collection brought by Sir Julius von Haast from the Canterbury Museum. The
teeth have evidently belonged to one fish ; but they are much confused, and do
not afford evidence of the actual position of the teeth in the mouth. They
are all thickly coated with a creamy white enamel. Some of the teeth are
erect, the lateral margins forming an equal angle with the base ; others present
a considerable obliquity, as represented in fig. 2. The erect examples, which
probably occupied an anterior position, near the symphysis of the rami of the
jaws, with a height of one inch, are 0*7 inch across the base of the crown. The
oblique teeth, from the posterior portion of the jaws, having the same length,
attain one inch across the base ; the posterior margin, one inch in length, concave
in outline, and the anterior one, convex, is 1*3 inch in length.

The root is large, prominent on the internal surface, and descending laterally

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 27

on each side to a depth, from the median bulb of the root, equal to the height of
the crown. The lateral projections of the root are strong and rounded, with a
deep concavity between them.

This species possesses characters readily distinguishing it from others pre-
viously described. Several characters of all the species of this genus exist in
common, such as the equilateral, elongated teeth occupying the front of the
mouth, and the more or less obliquely- arched teeth of the back. In this species
the sigmoidal curvature of the antero-posterior aspect of the tooth, and the great
length of the lateral prongs of the root distinguish it. It probably approaches more
nearly to Oxyrhina hastalis, Agass. ("Poiss. Foss.," vol. iii., pi. xxxiv., figs. 1—17,
p. 277), than to any other. From this it differs in the following particulars : —
0. hastalis is comparatively thin ; the prongs of the root are short, the posterior
teeth much less obliquely arched, the base of the enamel on the internal surface
of the crown forms a straighter line, and there is a median ridge extending from
the base three-fourths the height of the tooth on the external surface of the crown.
The anterior teeth of the species now described bear a superficial resemblance to
some of the teeth of Oxyrhina mantellii, Agass. [op. cit., p. 280, pi. xxxiii., figs.
1—9) ; but they are readily distinguished by the greater breadth of the posterior
teeth in proportion to the height of the crown. The deep concavity of the
posterior margin of the arched teeth, and the shortness of the root of 0. mantillii,
as compared with Oxyrhina von haastii, also indicate important differences.

A number of the teeth of Oxyrhina have been found by the Rev. J. E. Woods
associated with characteristic chalk fossils at Mount Gambier. They vary from
less than an inch to three or four inches in length, and have been named, but not
described, by Prof. F. M'Coy, " Oxyrhinus ivoodsii." A woodcut is given of the
teeth in " Geological Observations in South Australia," 1862, by the Rev. J. E.
Woods, which appears to indicate a somewhat close resemblance to 0. hastalis,
Ag. (see fig. 8, op. cit.), and shows them to be sufficiently distinct from the
species now described.

Formation. — Oamaru formation.
Locality. — Oamaru.

Ex coll. — Cambridge Museum, Christchurch ; Geological Survey Collections,
Wellington.

Oxyrhina recta, Davis.
(PI. v., fig. 14.)

The teeth of this species are of medium size, regular in outline, comparatively
thin, without outward flexure of the crown, and the root extends downwards with
widely-distended lateral prongs. The median height of the crown is 0-9 inch, the

E 2

28 Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand.

length of the lateral margin 1*15 inch, and the width across the base about 0*5
inch. The roots are extended to a width of 1*2 inch between their extremities.
The length of the root is equal to the height of the crown, each measured from the
middle of the base of the external surface of the crown. The external surface is
convex, only slightly less so than that of the internal aspect. Both ascend with-
out perceptible curvature from the base, and converge at the apex. The lateral
margins are thin and sharp, each with a slightly sigmoidal curvature ; the enamel
of the crown descends on each side, so as to envelop a considerable portion of the
lateral margin of the root. The base of the enamel on the external surface is
slightly concave, that of the internal surface is more deeply rounded. The root
is large, well-rounded on the internal surface, and descending on each side to a
considerable length, and terminating in a pointed prong. The root retreats on the
external surface, and is concave. The inferior surface between the prongs is
deepty concave.

This species is probably most nearly related to Oxyrhina von haastii, Davis,
especially in the extension of the prongs of the roots; the two may be distinguished
by the more divergent arrangement of the prongs in this species, and the prolonga-
tion of the enamel over the lateral surfaces of the root. The crown of 0. v. haastii
is curved externally ; in this one it is straight. The crown of the latter is
moderately convex on each surface, that of 0. v. haastii is externally flat, and
internally very much more convex. This tooth is considerably thinner than 0. v.
haastii. It also superficially resembles the anterior teeth of Oxyrhina enysii, Davis,
it differs in the convexity of the external surface, and its rectitude from the
base to the point without external flexure.

Formation and Locality. — Oamaru system ; Castle Hill Station, Canterbury.

Ex coll. — John Davies Enys, Esq.

Oxyrhina enysii, Davis.

(PL v., figs. 17-20.)

A large number of teeth of small and medium size have been obtained from
the Oamaru formation at Broken River, they are mostly oblique, occasionally
erect, lanceolate, acutely pointed, lateral margins smooth. The external surface
of the crown is almost flat, with a slight median depression near the base, the
point curved gently outwards. The internal surface is convex. The base of the
crown expands on both the external and internal aspects of the tooth, especially
the latter, where it has been attached to the cartilaginous jaw, apparently with-
out the intervention of an osseous root, there being no evidence on any of the
specimens of the existence of the latter. The enamelled surface extends in a line
almost straight across the external surface; that on the internal one is more or less

Davis — On Fossil-Fish Remains form the Tertiary Formations of New Zealand. 29

concave. The teeth exhibit considerable variation in form and size, the largest
are 09 inch in length, those obliquely curved are widest at the base, the width
equalling two-thirds of the height ; they were probably situated on the posterior
part of the jaws. The straighter anterior teeth are little more than half the
width of their height.

Teeth of the same genus, and apparently of the same species, have also been
found in the Waipara formation. They exhibit a greater amount of obliquity,
but otherwise do not materially differ from those of the Oamaru rocks.

I have pleasure in suggesting the specific appellation Oxyrhina enysii, in
recognition of the services rendered to palaeontological science by Mr. J. D. Enys.

Formation and Locality. — Oamaru formation ; Broken River and Waipara
formation, Waipara.

Ex coll. — J. D. Enys, Esq., Otago Museum; Canterbury Museum, Christchurch.

Oxyrhina acuminata, Davis.
(PL v., fig. 21.)

The beautiful example which forms the basis of my description of this species
was collected and forwarded to me by John Davies Enys, Esq., of Canterbury.
The tooth is lanceolate, slightly arched backwards, the point curved outwards ; its
median length from the base of the crown to the apex is 1*9 inch; the length of
the anterior lateral margin 2*2 inches, and that of the posterior margin 2*0 inches,
the latter slightly concave, the former convex. The width of the base of the
crown is 1*2 inch ; for the root must be added half an inch to the length and
its greatest width is 1*3 inch. The lateral margins of the tooth are smooth and
sharp, converging and forming an acutely-pointed apex. The external surface is
slightly hollowed, especially the upper part; towards the base the hollow descends
on each side, and the median portion is a little raised. The internal aspect of the
tooth is gently convex ; the base of the enamel forms a well-pronounced curve, much
more so than that of the external surface. The root is concave externally, and
gently convex on the opposite surface ; the lateral extensions are not very
pronounced, extending downwards somewhat less from the base of the crown than
the median portion ; the inferior surface conforms roughly to the concave margin
of the base of the crown on the external surface.

This species differs from Oxyrhina von haastii by the small dimensions of its
root, by its lanceolate outline, the highly-curved point, and more especially in the
smaller breadth between the external and internal surfaces, due to the comparatively
small convexity of the internal surface of this species as compared with 0. von haastii.

The elongated teeth of Oxyrhina xiphodon, Agass. (" Poiss. Foss.," vol. iii., p. 278,
pi. xxxiii., fig. 12), resembles this one in general outline, but may be distinguished

30 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

by the median depression of the internal surface of the crown, and in the base of
the enamel being equally curved on both the external and the internal surface.

Formation. — Oamaru formation.

Locality. — Castle Hill Station, near Canterbury, New Zealand.
Fx coll. — John Davies Enys, Esq.

Oxyrhina yrandis, Davis.

(PL v., figs. 15, 16.)

Teeth much elongated, thick and strong, point curved outwards ; length of
crown 1*8 inch, breadth at base 0*7 inch. The external surface slightly but
uniformly convex from the base to the apex. The internal surface deeply convex,
expanding towards the base, and curving near the apex over towards the external
aspect. The lateral margins more or less equidistant and produced so as to form
a sharp cutting-edge. Root not sufficiently well preserved to afford reliable
indications of its form. Other specimens from the same beds, probably of the
same species as those described, are somewhat shorter in proportion to the length,
and are arched in an oblique direction backwards, the latter have probably been
derived from the posterior part of the mouth, and the longer teeth from the
anterior. The characteristics of this species which distinguish it from others are,
the great length in proportion to the width, and the semi-rotundity of its
horizontal section, produced by the double convexity of both the internal and
external aspects. Whilst Oxyrhina acuminata may be distinguished by its thinness
in proportion to its length and breadth, this species may be equally well recognised
by its thickness or rotundity, as compared with the length and breadth of the
tooth.

Formation. — Oamaru and Waipara systems ; Cretaceo-Tertiary.

Localities. — Broken River ; Curiosity Shop ; Wekapass ; Greensand conglome-
rate, South Wing, Amuri Bluff ; Amuri Limestone, Amuri Bluff.

Ex coll. — Canterbury Museum, Christchurch ; Geological Survey Collections,
Wellington.

Oxyrhina fastiyata, Davis.
(PI. vi., figs. 1-3.)

A large number of small teeth, not more than half an inch in length, and
about half that in breadth across the base, occur in the Oamaru formation,
principally in Coleridge Gully. The form varies according to the position which

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 31

the teeth have occupied in the mouth, a proportion being erect with equilateral
margins, others arched more or less obliquely backwards. The external surface is
convex, but to a smaller extent than the internal one. The base of the crown
extends in an almost straight line across the tooth on the external surface, with a
slightly upward tendency on the internal one. The base of the crown on the
latter surface is produced outwards, whilst that of the external surface is
correspondingly depressed, and forming a hollow which ascends a short distance
on the enamelled crown. The crown is enveloped in enamel, smooth and
unstriated. The root is moderately large, extending backwards, and forming a
well-rounded bulbous prominence on the internal surface ; a correspondingly deep
concavity exists on the external face. The concavity of each succeeding tooth
fitting to the bulbous prominence of the one before it.

The teeth now described are separated from those of Oxyrhina enysii, Davis,
by their elongated form, and the narrowness of their base in proportion to their
height. The obliquely-curved posterior teeth of 0. enysii are, in some of the teeth
exhibiting greatest curvature, and probably derived from the most posterior part
of the jaw, as broad across the base as the length of the concave, or shorter
lateral margin, a feature which immediately distinguishes them from this species.
The external surface of the latter is convex, whilst that of 0. enysii is flat, or
nearly so.

Forma tion. — Oamaru form ation .

Locality. — Coleridge Gully.

Ex coll. — Canterbury Museum, Christchurch.

Oxyrhina subvexa, Davis.
(PI. vi., fig. 4.)

The type of this species is a single specimen from Hog's Back, New Zealand,
collected and sent by Mr. J. Davies Enys. Its nearest relationship appears to be
with Oxyrhina von haastii, Davis ; it is, however, so dissimilar from the teeth of
that species that it is undesirable to place it with them, and it is therefore treated
as a separate species. The discovery of additional specimens may prove the
correctness, or otherwise, of this determination. The tooth was probably situated
on the posterior part of the jaw; it is arched, with a slight obliquity backwards ;
the height along the median line is 1*1 inch; the posterior margin TO inch, and
the anterior one 1*2 inch; the base of the crown is 0'7 inch across. The
external surface presents a somewhat undulating appearance. Midway between
the base and point the central part of the tooth is concave, from the centre it rises
on each side, as well as towards the point and the base, and forms a slight convexity.

32 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

The base of the crown is plicated, the folds extending about 0-2 of an inch
upwards. A groove also extends from the base to the point along eacli lateral
margin, rendering the margins thin, almost transparent. The internal surface is
moderately convex ; towards the base it becomes greatly expanded, indicating a
large root; the latter is, however, unfortunately absent. The anterior lateral
margin is convex, except towards the base, where it turns outwards over the root.
The posterior margin is concave for one-third its length from the point, deeply
so for a similar distance from the base, the intermediate third being convex.
The external base of the crown is straighter, and descends lower, than that
of the internal surface.

Forma Hon. — Oam ar u sy s tern .
Locality. — Hog's Back.

Ex coll. — John Davies Enys, Esq., Canterbury, New Zealand.

Oxyrhina lata, Davis.
(PI. vi., fig. 5.)

Teeth pyramidal in outline, equilateral. Crown 0*5 inch in height, 0'4 inch
across the base. External surface slightly convex, with minute sulci at the base ;
lateral margins straight, smooth ; apex acutely-pointed. Internal surface for the
most part hidden in the matrix ; upper part exposed, convex. Root large and
strong, broader than the base of the crown. Line dividing the crown from the
base on the external surface straight.

Oxyrhina lata is distinguished from all the New Zealand species by the great
breadth of the base of the crown as compared with its height, and the straight
lateral margins. These peculiarities serve also to separate this species from others
previously described. Oxyrhina triyonodon, Agassiz ("Poissons Fossiles," vol. iii.,
p. 279, pi. xxxvu., figs. 17, 18), from the Tertiary strata of the valley of the Rhine,
is characterized by its very regular form representing an isosceles triangle, and the
thinness of the tooth. The base of the tooth in the species now described
represents a tooth of considerable thickness, and the uniform, though slight,
convexity of the external surface differs from that of 0. triyonodon, which has a
groove running parallel with the margin on each side. The latter is a large tooth
two or three inches in length, which further separates it from this species, which is
a small tooth.

Forma Hon — Oamaru system .

Locality. — Kakahu River, South Canterbury, New Zealand.
Ex. coll. — Prof. F. W. Hutton, Otago Museum, New Zealand.

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand. 33

Family. NOTIDANIDiE.

Genus. Notidanus. Cuvier.

Dentition unequal in the jaws; in the upper jaw one or two pairs of awl-
shaped teeth, the following six being broader and provided with several cusps,
one of which is much the strongest. Lower jaw with six large comb-like teeth on
each side, besides the smaller posterior teeth. Spiracles small, on the side of the
neck. No pit at the root of the caudal fin. Gill openings wide ; six in number
in Hexanchus, seven in Heptanchus. One dorsal fin only, without spine, opposite
to the anal (Giinther).

Notidanus primigenius, Agass.
(PI. vi., fig. 6.)

Notidanus primigenius, L. Agassiz, 1843, . " Poiss. Foss.," vol. iii., p. 218,

pi. xxvii., figs. 4-8, 13-17.
,, recurvus, . ,, 1843, . Op. cit., p. 220, pi. xxvil, figs.

9-12.

,, primigenius. R. W. Gibbes, 1849, " Journ. Acad. Nat. Sci.,Philad.,"

ser. 2, vol. i., p. 195, pi. xxv.,
fig. 95.

„ „ A. Quenstedt, 1852, .. "Handb. Petrefakt.," p. 167, pi.

xiii., fig. 3.

„ „ J. Probst, 1858, . " Wurttb. Jahreshefte," vol. xiv.,

pp. 124-127.

„ „ R. Lawley, 1877, . "Atti Soc. Toscana Sci. Nat.,"

pp. 66-68, pi. i., figs. 1-5.

,, recurvus, . ,, 1877, . Op. cit., pp. 69, 70, pi. n., fig. 1.

„ „ J. Probst, 1879, . "Wurttb. Jahresh.," vol. XXXV.,

pp. 162, 163, pi. in., figs. 12-17.

,, primigenius, ,, 1879, . Op. cit, pp. 158-162, pi. m.,

figs. 1—5.

„ ,, F. Noetling, 1885, . " Abh. Geog. Specialk. Preussen

u. Thiiring. Staaten," vol. vi.,
pt. 3, pp. 17-19, pi. i., figs. 4, 5.

„ „ A. S. -Woodward, 1886. " Geol. Mag. N. S.," Decade 3.,

vol. iii., p. 2 16, pi. vi., figs. 19-22.

A single tooth of the upper jaw, of this species, is included in the collection
forwarded by Prof. Hutton from the Otago Museum. The crown consists of three
principal cones ; the largest is 0*4 inch in height, 0-3 inch in breadth at the base.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART I. F

3 ± Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

The lateral margins converging to an acute apex inclined obliquely backwards.
Surface of cone convex, with margins smooth and thin. At the base of the
anterior margin is a series of six or seven minute denticulations connecting it with
the base. The second cone is much smaller than the first ; its length is 0*15 inch,
and its breadth at the base is equal to the length. It is more obliquely inclined
backwards than the larger cone. The third cone is still smaller ; it is broken off,
but its form and size are indicated on the matrix. Its point is much more obtuse
than the others. The surface of the whole is enveloped in smooth shining enamel.
The root is large and massive, equalling in depth the height of the largest cone.
It is compressed laterally.

The example now described approaches most nearly in form to the tooth
figured by Prof. Agassiz (" Rech. sur les poiss. foss," vol. iii., pi. xxvu., fig. 9) as
Notidanus reenrvus, which appears, as already pointed out by Mr. A. S. -Woodward
("Geol. Mag.," Decade 3, vol. iii., p. 217), to be an upper tooth of this species.
The specimen in the collection of Dr. Reed, now in the York Museum, derived from
the Red Crag of Woodbridge, in Suffolk, and figured by Mr. A. S. -Woodward
(op. cit. pi. vi., fig. 21), is almost identical in size and proportions with the one
from New Zealand. This species, which appears to have as wide a range over
the surface of the globe as any species hitherto recorded, has been found in the
Tertiary beds throughout Europe ; it is recorded in America, and the specimen
now described extends its range to the opposite extreme of the world.

Formation. — Oamaru formation.

Locality. — Cave Valley, Oamaru ; Coleridge Gully.

Ex coll. — Prof. F. W. Hutton, Otago, New Zealand.

Notidanus marginalis, Davis.
(PI. vi., figs. 7, 8.)

Teeth of both the upper and lower jaws have been found of this species. They
were obtained by Mr. J. Davies Enys, from the Oamaru formation at Castle Hill
Station. The teeth from the upper jaw are moderately large and thick. The
crown consists of one large cone, occupying two-thirds the breadth of the tooth,
the remaining posterior third consisting of about a dozen small denticulations
diminishing in size backwards, excepting the two first, which are very small. The
large cone rises 0*4 inch from the base, and is inclined backwards; the external
and internal surfaces are convex ; its posterior margin straight and smooth ; the
anterior one is convex, very long, and serrated from the base almost to the apex ;
the serrations are largest midway between the two extremities, towards which they
gradually diminish in size. The external surface of the base of the crown is
slightly curved inwards ; a corresponding convexity characterizes the internal

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 35

surface. The line dividing the crown from the root ascends higher on the internal
than on the external surface, in this respect conforming to the ordinary character
of the selachians. The root descends 0*1 inch; on the external surface its lower
margin is arched upwards, parallel to the outline of the base of the crown, from
which it is somewhat retrogressive ; the internal surface of the root is prominently
convex ; the median portion is 0*2 inch in depth. The breadth is 0*8 inch.

This tooth is readily distinguished from the upper teeth of Notidanus primigenius,
from the Cave Valley deposits, by its single large cone, the great length of its
anterior margin, and the comparatively small size of the root. These features also
serve to distinguish it from other species previously described.

The teeth of the lower jaw are thinner and less robust than those of the upper
one, the crown is more slender and the root deeper. The breadth of the tooth
figured is nearly I/O inch ; the height of the crown is 0*25 inch, and the depth of
the root 0-2 inch. The external surface is straight or very slightly concave, that
of the internal one slightly convex. There are five cones decreasing in size back-
wards ; they have an oblique inclination in the same direction. The anterior
margin at the base of the first or largest cone has five or six serrations, decreasing
in size towards the root, and at the posterior extremity of the tooth there is also a
minute denticulation. All the cones are smooth and convex on each surface. The
root is moderately large, but thin ; its internal surface at first produced rapidly,
declines towards its base and thins out to a knife like edge. It rises higher on the
internal than on the external surface.

The teeth of the lower jaw bear a tolerably close resemblance to those of
Notidanus serratissimus, Agass. (" Poiss. Foss.," vol. iii., p. 222, pi. xxxvi., figs. 4, 5),
and also to the tooth figured by Mr. A. Smith-Woodward (op. cit., fig. 23), from the
London clay. The teeth of the mandible of N. primigenius, Agass., might also be
confounded with it ; but its association in the same beds with the maxillary teeth
described above leads to the inference that they were associated and belong to the
same species, and if this be the case, the resemblance of the teeth of the lower jaw
to those of other species must be received as accidental; the teeth of the upper jaw
are distinctly separated from any others previously described.

Several single denticles, probably belonging to this species, occur in the
collections received from the Canterbury Museum, Christchurch. They were
obtained from the Oamaru series at Coleridge Gully. The denticles are from the
teeth of the lower jaw, and the same size as the larger denticles of the specimen
figured.

Formation. — Oamaru formation and Waipara formation (Te A ute series).
Locality. — Castle Hill Station, Canterbury; Waipara; Tata Island Limestone,
Nelson.

Ex coll. — J. Davies Enys, Esq., Canterbury, New Zealand; Canterbury
Museum, Christchurch.

F 2

36 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

JYotidanus dentatus, Smith-Woodward.
(PI. vi., figs. 9-12.)

A. Smith-Woodward, 1886. " Geological Magazine," Dec. 3., vol. iii., p. 214,

PL vi., figs. 17, 18.

In 1876 Sir J. Hector sent a small collection of fossil-fish remains to the British
Museum. They were obtained from Amuri Bluff, New Zealand ; and amongst
them were specimens of the teeth of a large Notidanus. These were described by
Mr. Smith-Woodward, in the Paper cited above, in the following terms : —

" The lower tooth exhibits three small denticles in front of the principal cone,
the first being the largest, and having a recurved apex, the second slightly
smaller, with straight, but backwardly- directed point, and the third very much
more minute. Behind the principal cone, which is scarcely more robust than that
immediately following, there are ranged three other cones, of gradually diminish-
ing size ; and posterior to these a minute denticulation is visible. In the upper
tooth the principal cone appears more definitely contrasted with the others. In
front there are two distinct denticles, the first being three times the size of
the second ; and the principal cone itself is placed almost vertically with respect to
the base-line of the crown, although its anterior edge has a much less abrupt slope
than the posterior. Behind this there are three other cones rapidly diminishing
in dimensions : the first somewhat inclined backwards, and three-fourths the size
of the principal cone ; the second backwardly directed at a corresponding angle,
but only about one-third as large as the first ; and the third a minute, broad,
acuminate denticle. Though now imperfectly shown, the base-line of the crown
was obviously arched ; and the remains of the root indicate the usual configuration
and robust proportions of an upper tooth."

Two specimens of the teeth of the lower jaw are figured on PI. vi., figs. 11, 12.
They are from the Geological Survey Collection forwarded by Sir James Hector,
M. D. The teeth are larger than the tooth described by Mr. Smith-Woodward,
but in other respects appears to be the same. The tooth represented by fig. 11
has nine denticles preserved ; and the other one has the still larger number of
eleven ; the type described by Mr. Smith- Woodward has not more than eight
denticulations.

The species thus described most closely approximates to the characters pos-
sessed by JV. pectinatus from the English chalk. The latter, however, is much
smaller, and differs in possessing a longer series of cones behind the principal. It
is also stated to possess characters in common with a small species at present
existing in the seas off the coast of Patagonia, described by Mr. S. Garman

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neio Zealand. 37

("Bulletin, Essex Institute," vol. xvi., pp. 56, 57: 1884) as a new species,
N. pectorosus. The latter is a small species, only sixteen inches in length, and has
one cusp fewer than N. dentaius.

Formation and Locality . — Waipara formation ; Amuri Bluff ; Waireka series ;
Amuri Bluff (Sir J. Hector).

Ex coll. — British Museum, Natural History, Cromwell-road, London; Geological
Survey Collection, Wellington.

(B) — B ATOIDEI — KAYS .

Family. TRYGONTDiE.

Genus. Trygon. Adanson.

The pectoral fins are uninterruptedly continued to, and are confluent at, the
extremity of the snout. Tail very long, tapering, armed with a long arrow-
shaped, barbed spine. Body smooth or with tubercles. Vertical fins none.
Nasal valves coalescent into a quadrangular flap. Teeth flattened.

Trygon ensifer, Davis.
(PI. vi., figs. 13-15.)

A number of fragmentary remains of the teeth and dermal osseous tubercles,
together with specimens in good preservation of the spines of a species of Trygon,
have been found in several localities in the Oamaru and the uppermost beds of the
Waipara formations. Calculating from a comparison of the size of the spine and
teeth with those of an existing species, it is probable that the fossil-fish attained a
size of about one foot in diameter. It is somewhat difficult to distinguish between
the dermal tubercles and the teeth. Certain patches of sub-quadrate ossicles, with
one angle of the square pointing forwards, are regarded as teeth, whilst the larger
proportion of the specimens are more or less round, with flattened surfaces, and
probably pertained to the dermal series of tubercles.

The teeth vary in size from 0*1 inch to 0*05 inch in width. They have an
imbricated arrangement, the anterior point of a tooth overlapping slightly the
margins of those in front of it. The surface where not worn is prominent and
rounded, but where the teeth have been much used they are worn smooth, and
present an even pavement-like arrangement. They appear to be firmly attached

38 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

to the jaws, a portion of the bony substance of which has, in some cases, broken
away, and remains attached to the teeth. The teeth are covered with enamel.
The under surface is more or less hollow.

The dermal tubercles have a circular outline with a convex surface. Where
they present an hexagonal form they have the appearance of having had all the
corners rubbed off. The surface is often considerably worn. The depth of the
tubercles is small ; and they are deeply concave beneath. They present much
difference in size, individual specimens being 02 inch in diameter.

A spine, which is nearly perfect, is 0*6 inch in length and 0*1 inch across the
base. It is erect, compressed ; the lateral margins are armed with a row of firmly-
attached recurved denticles, which extend from the point two-thirds the length of
the spine ; towards the base they become smaller, and gradually disappear.
The anterior and posterior surfaces are slightly convex, with a smoothly enamelled
surface. An internal canal extends from the base towards the apex. A second
example (fig. 15), is longer and differs from the other which is represented, in the
much smaller denticulation of the margin; it is from the chalk series of Amuri
Bluff, and has been forwarded by Sir James Hector, M.D., with others from
the Survey Collections at Wellington Museum.

Prof. L. Agassiz states that two species of Trygon have been found, viz.
T. gazzolce and T. oblongus (u Poissons Fossiles," vol. iii., p. 382**). They are
from the strata of Monte Bolca, but are not described. The specimens which are
the subject of this description are very similar to some of the existing forms. It
is proposed to designate this species by the name Trygon ensifer, having re-
ference to the small sword-like spine.

Formation. — Uppermost bed of the Waipara and the Oamaru formations ; Te
Aute series and Chalk series.

Localities. — Waipara, Wekapass ; Colebridge Gully ; Broken River ; Castle
Hill, Canterbury ; Tata Island Limestone, Nelson ; Amuri Bluff ; Kakahu ;
Coleridge, Trelissic, Canterbury ; Waihola series, Otago.

Fx coll. — Canterbury Museum, Christchurch ; J. D. Enys, Esq., &c, Geolo-
gical Survey Collections, Wellington.

Family. MYLIOBATIDiE.

Genus. Myliobatis. Dumeril.

The disk is very broad, in consequence of the great development of the
pectoral fins, which, however, leave the sides of the head free, and reappear at the
extremity of the snout as a pair of detached cephalic fins. Viviparous, teeth
hcxangular, large, flat, and tesselated, those in the middle much broader than long,

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand. 39

several narrower series on each side. Tail very long and thin, with a dorsal fin
near its root ; generally a serrated spine behind the fin.

A large number of specimens of this genus have been found in the Oamaru
formations at Broken River, Curiosity Shop, Castle Hill, and other localities.
They present characteristics which appear to necessitate their division into three
species. There are probably more than this number, but their isolated or detached
state of preservation renders their determination difficult.

Myliobatis plicatilis, Davis.
(PI. vi., figs. 16-19.)

A large number of teeth, all disconnected from each other, and many of them
broken, have been found in the Oamaru formation ; they are straight or very
slightly arched, and vary from 0-3 of an inch in breadth to 1*8 inch. The
larger ones are generally much worn by attrition on the upper surface, but, as
might be expected, not all to the same extent. The upper surface, where not
much abraded, is smooth and covered with glistening enamel; in examples in
which the abrasion has proceeded to a greater extent the surface has a coarse
osseous ajDpearance. An example, 1*7 inch in breadth is 045 inch in length in the
centre, diminishing towards each lateral extremity to 04 inch. The base of the
crown descends obliquely backwards, the division between the crown and root
being marked by a prominent ridge which encircles the whole tooth. The root is
slightly less in breadth and length than the crown ; it is composed of a variable
series of lamellse descending from the base of the crown, each parallel with the
others and separated by an interstice equal to the width of the plate. The number
of lamellse depends to some extent on its age : the small specimens have compara-
tively few, whilst those of mature growth are possessed of from thirty to forty.
The anterior portion of the crown projects beyond the root, whilst behind the root
extends a similar distance beyond the crown — an arrangement similar to that found
in existing species, and serving to attach and interlock the succeeding teeth.
The lateral extremities of the tooth are angular, the median portion produced so
as to fit to the small lateral teeth. Several of the latter occur, one 0*4 inch in
length, the same length as the specimen described above, from the centre of the
palate is 0*1 inch in breadth in the middle, tapering to a point before and behind;
others are slightly broader than this in the median part. The roots of the small
lateral teeth have two or three parallel antero-posterior lamellee, or ridges. Others
of the small lateral teeth are angular along one of the lateral margins, and convex
on the other, and were doubtless the external components of the palate ; they are
in other respects similar to, and the same size as, those already described.

This species is readily distinguished from those previously described by the

40 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

comparatively small breadth of the crown as compared with its length. This
character separates it from Myliohatis goniopleurus, Agassiz ("Poiss. Foss.," vol.
iii., p. 319, pi. xlvii , figs. 9, 10), obtained from the London clay of Sheppey, in
which teeth of the same length are nearly twice the breadth. From M. toliapicus,
Agass., (op. cit., p. 321, pi. xlvii., figs. 15-20), it may also be distinguished by its
narrow four-sided lateral teeth, those of 31. toliapicus being regularly six-sided.
The fossil species bears a passing resemblance to the existing 31. aquila, but differs
from it in the form of the large central plate, which in the recent species is curved
in outline, with a much shorter crown compared with its length.

Formation. — Oamaru formation.

Locality. — Curiosity Shop ; Broken River; Castle Hill Station, &c. ; Coleridge;
Trelissic ; Tokmairiro Limestone, Waihola Gorge.

Ex coll. — Canterbury Museum : J. D. Enys, Esq. ; Geological Survey Collec-
tion, Wellington.

Myliohatis arcuatus, Davis.

(PI. vi., figs. 20, 21.)

A second species of this genus from the Oamaru beds is represented by a large
number of specimens. It is smaller than 31yliohatis plicatilis, and differs from it
in the shortness of the crown as compared with its breadth and in its highly-curved
outline. A fully mature and much abraded example is 13 inch in greatest
diameter between the two lateral extremities, the length of the crown being 0*2
inch. The surface of the crown is somewhat rough and fibrous. A ridge, similar
to the one on 31. plicatilis, indicates the division between the root and the crown,
whilst the latter shows a considerable obliquity in the relative position of the
crown and root ; the species now described is more erect, and its thickness greater.

Formation and Locality. — Oamaru formation ; Castle Hill Station.
Fx coll. — J. D. En}^s, Esq. ; Cambridge Museum.

Myliohatis alius, Davis.
(PI. vii., figs. 1, 2.)

Specimens of parts of two palates have been obtained from the Oamaru forma-
tion at Broken River, they are each fragmentary, but exhibit three teeth in situ in
one specimen, and two in the other. The length of the teeth is 0'5 inch, the
breadth is not preserved, the height between the crown and the root is 0*5 inch.
They are large and massive ; the surface of the crown between the lateral ex-
tremities is deeply convex, and in the antero-posterior direction the palate is also

Davis — On Fossil-Fish Remains from the Tertiary Formations of 'New Zealand. 41

convex. The surface of the crown is smooth, with a more or less fibrous
appearance. The under surface of the root is devoid of lamellae, but presents an
open and porous structure. The root occupies about one-fourth the entire height
of the tooth. The teeth decrease in thickness towards the margin, and in the
specimen now described there is attached thereto a single row of lateral teeth. If
there were other rows they have disappeared. The lateral teeth are small, 04
inch in length, and not more than Ol inch across laterally.

The presence of the lateral plates prove these teeth to belong to a species of
Myliobatis, and the thick convex median teeth appear to separate this from any
other species previously described. The massive character approaches most nearly
to that of M. regley, Agass. (" Poissons Fossiles," vol. iii., p. 320, pi. xlvi.,
figs. 6-11), obtained from the neighbourhood of Brussels in Belgium. The latter,
however, is founded on a single fragment without lateral plates, and all the edges
broken off, so that it is very difficult to compare the specimens now described with
those of Agassiz species. So far as the form of the coronal surface is concerned
the sutures dividing the large median plates in M. regley are straight, whilst in
this species they are curved. The under surface of the root in the former is
lamellated; in this species lamellae are absent.

Formation and Locality — Oamaru formation : Broken Eiver.
Ex coll. — Canterbury Museum, Christchurch, New Zealand.

Sub-order 2. Holocephala.
Family. CHIMERID2E,

Callorhyncns hectori, Newton.

Newton, E. T., 1876, ''Quart. Journ. Geol. Soc," vol. xxxii., p. 329, pi. xxi.,

figs. 6—9.

(PI. vii., figs. 14, 15).

The single specimen on which this species is founded was placed in the British
Museum by Sir J. Hector. It is a right maxilla, a little more than one inch
in length and three-fourths of an inch in width at its posterior widest part. The
lower or oval surface is exposed, the upper one imbedded in the matrix. The oval
surface of the maxilla is provided with a single tooth, composed of dentinal
substance ; posteriorly this appears to pass into the substance of the bone ; but
anteriorly it is prominent and divides into two divaricating branches with a
depressed area between. These are worn by impact with the opposing surface of

TRANS. ROY. DUB. SOC, N.S. VOL. TV., PART I. G

42 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

the single tooth of the mandible. A comparison of the specimen with the jaws
of the existing Callorhynchus anlarcticus shows that there is a close resemblance
between the two. The tooth of the New Zealand fossil is flatter, larger, and has
longer anterior prominences than the existing species ; and whilst it is regarded
by Mr. Newton as undoubtedly being the same genus, he considers it forms
a different species which he has distinguished by appending the name of Sir
J. Hector.

Formation. — Black Grit series ; Cretaceo-Tertiary.
Locality. — Amuri Bluff, New Zealand.

Ex coll. — British Museum (Natural History Department); Geological Survey
Collection, Wellington.

Ischyodus brevirostris, Agassiz.

Newton, E. T., 1876. "Quart. Journ. Geol. Soc," vol. xxxii., p. 326, pi. xxi.,

fig. 5.

(PI. vii., figs. 10-13.)

The unique specimen described by Mr. Newton is from the Amuri Bluff Beds,
and was deposited in the British Museum by Sir J. Hector. It is the right mandible,
and its outer surface is embedded in the matrix, and part of the narrow extremity
of the tooth is broken off. It is described as in all essential respects similar to the
teeth of Ischyodus brevirostris, named, but not described, by Prof. L. Agassiz
(" Rech. sur les Poiss. Foss.," vol. iii., p. 344). The English types of Agassiz are
from the phosphatic deposits of Cambridge. The New Zealand example is shorter
along the oval margin, and the centre of the tooth is more prominent than in
the specimens from the Cambridge Greensands.

Three additional specimens are represented from the collections of the Geolo-
gical Survey. Figs. 11 and 12 exhibit the under surface of the jaw, and fig. 13 a
fragment of the upper surface.

Formation. — Coal-Beds, Cretaceo-Tertiary formation.
Localities. — Amuri Bluff Beds ; Kakohu River, South Canterbury.
Ex coll. — British Museum (Natural History Department) ; Geological Survey
Collection, Wellington.

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 43

Sub-class II. — TELEOSTEI.
Order 1. — Acanthopterygii.
Division I. — Acanthopterygii Perciformes.
Family IV. SPARID-ffi.
Genus. Sargus. Cuvier.

Agassiz, L., 1833—4. "Rech. sur les Poissons Fossiles," vol. iv., p. 168.

The genus Sargus is restricted to the species of Sparides, which have rounded
molars posteriorly. The anterior teeth of each row are disposed in a single row
on the extremities of the intermaxillaries and the inferior maxillaries. They
are compressed and spatulate, the extremities truncated like the incisors of the
Rodents.

Sargus laticonus, Davis.
(PI. vii., figs. 3-8.)

A large number of teeth have been found in the limestone beds at Coleridge
Gully, Broken River, Castle Hill, and other places. They vary considerably
in form and size, ranging between a round, conical, upright tooth, to others which
are oval in section at the base with spatulate crown, compressed antero-posteriorly,
and presenting an appearance similar to the incisors of the recent Sargus. The
apex of the tooth is in most instances worn off by attrition, often to such an extent
as to expose a section of the tooth ; where the apex is still preserved it is blunt
and rounded. The teeth are all enveloped in a strong and thick coating of
enamel, with a polished smooth surface. An example (fig. 3) of the round conical
form of comparatively large size is 0*5 inch in length from the base of the crown
to the apex, the latter bluntly rounded, and the base is 0*3 inch in diameter. The
cone is slightly twisted ; otherwise it ascends with a tolerably uniform contour.
The base of the crown is slightly contracted, and forms a well-defined line of
division between the crown and the root. The root in this specimen is broken off ;
but in others of similar form it is equal in depth to the height of the crown (fig. 4).
Its upper part, where joined to the crown, is contracted and less in diameter
than the base of the crown ; it increases lower down, and becomes considerably
wider than the crown, still preserving its rotund section. The outer surface of the

G 2

44 Davis — On Fossil- Fish Remains from the Tertiary Formations of New Zealand.

root is fine and fibrous, rather thin as compared with the enamel of the crown,
which will probably account for their being so frequently detached. The interior
of the root is apparently composed of a more or less spongy mass, hollow in the
centre. The hollow ascends the crown, gradually disappearing towards the point.
The height of the conical tooth now described, as compared with its diameter, at
the base of the crown, bears the proportion of five to three ; other examples vary
as four to three ; and instances are not unfrequent in which the diameter equals
or even exceeds the height, excluding those specimens which are worn.

An example selected from the opposite, or most compressed type of the series
(fig. 5), is 0*3 inch in diameter at the base of the crown, between the two sides of
the tooth, and 015 from front to back; the height of the crown on the external
surface is 0*45 inch, being greater than the internal one, the margin of which is
slightly curved upwards. The external surface is convex, the lateral margins
rounded, and the internal surface is concave, sometimes quite spatulate. The apex
is usually considerably worn and angular; occasionally it is obtusely pointed.
The base of the crown is slightly contracted laterally; and the root assumes a
form similar to that of the teeth, with conical crowns (fig. 6), except that
its diameter does not equal that of the breadth of the crown. Between the two
forms described every gradation may be found existing in the collections at my
disposal. The most extreme of the compressed type of teeth is a specimen (fig. 7),
in the collection of J. Davies Enys, from Castle Hill Station, near Canterbury.
It is 0*4 inch in breadth, very thin in section, and only 0*25 inch in height. It is
considerably worn, and has probably belonged to an aged fish.

This group of teeth appears to be closely related to the fishes comprised in the
family Sparidse, whose dentition consists either of cutting teeth in front of the
jaws or molar teeth on the sides ; generally palatal teeth are absent ; but in some
instances, as in the genus Sargus, in addition to incisors in the anterior part of the
lower jaw and the intermaxillaries, there are rounded, flat teeth, occupying an
intermediate position on the palates. The teeth from New Zealand differ from
those of the existing Sargus in the variety of their form, and in the absence of the
flat, circular palatal teeth. The teeth of Dentix, Agassiz (" Poiss. Foss.," vol. iv.,
p. 143) are long, conical and pointed, disposed in a single row. In the sharply-
pointed character they differ from the obtusely-pointed, conical teeth now
described, and are readily distinguished from the compressed incisor form.
They have probably a greater resemblance to the existing genera Sphserodon or
Lethrinus, which have canine teeth in front and a single series of broadly-conical,
molar -like teeth on each side ; or to some of the genera of the Cantharina, in
which the front teeth have a more or less broad, cutting surface, sometimes lobate.
The fossil genus Sparnodus, Agassiz (" Poiss. Foss.," vol. iv., p. 155), from the
Tertiary strata of Monte Bolca, possesses teeth which are large, conical, very
strong, and obtuse, eight occupying the front part of each jaw. They have

Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand. 45

usually been found associated with the remaining portions of the skeleton of the
fish. Some of the teeth described above, though isolated and detached from any
part of the skeleton of the fish, appear to approach very nearly to the teeth of this
genus. But the presence of a large proportion of the spatulate cutting teeth
prevents their association with the genus, whilst they indicate a clear relationship
with the genus Sargus, in which it is proposed they shall be incorporated with the
specific distinction Sargus laticonus.

Three examples of Otoliths (fig. 21) occur associated with the teeth of this
species. They are 04 inch in length, the upper surface convex, with radiating
sulci, most pronounced towards the margin, and a ridge along the median line ;
the under surface is slightly concave.

Formation. — Oamaru system ; Mount Brown series.

Localities. — Coleridge Gully ; Broken River ; Castle Hill Station, &c. ; Cole-
ridge ; Trelissic ; Canterbury.

Ex coll. — Canterbury Museum and College; J. D. Enys, Esq. ; Otago Museum;
Geological Survey Collections, Wellington.

Class.— MAMMALIA. Sub-class. — CETACEA.

Family. ZEUGLODONTID^].

Genus. Squalodon. Grateloup.

Squalodon. Grateloup. " Actes Acad. Roy. Sci., Bordeaux," 1840, p. 208.
Phocodon. Agassiz, . " Rech. sur les Poissons Fossiles," vol. iii., p. 255.

Molar teeth, with a semi- elliptical crown, strongly compressed laterally, the
cutting edge divided into semi- elliptical lobes in one plane, the middle one largest,
the lateral gradually diminishing to the anterior and posterior ends; enamel
longitudinally marked with small irregular ridges ; root with two or three fangs.
(M'Coy.)

This remarkable genus forms part of the Zeuglodontidse, a family of extinct
carnivorous whales, whose remains have been found in America, Europe, and
Australia ; in each instance in strata of Tertiary age. The Zeuglodonts of
America are from the Eocene formations ; in Europe the family is represented
by Squalodon grateloupi von Meyer, from the French Miocene beds near Bordeaux,
the only other examples are from beds of similar age at Le"ognan, in Gironde.
(M. Grateloup's type was a jaw from those beds, supposed to be of an animal
intermediate between sharks and saurians) ; and St. J ean de Videy, Herault, and
in Austria its remains have been found near Linz. Teeth of Squalodon, or

4(> Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

Pliocodon, have also been discovered in the Miocene strata of Malta. More
recently Prof. M'Coy has described a species of Squalodon from the Miocene
sands of Castle Cove, Cape Otway Coast, Australia, (" Geol. Mag.," vol. iv.,
p. 145, pi. viii., fig. 1, 1867, and " Proc. of the Palaeontology of Victoria,"
Dec. 2, pi. xi., fig. 1, 1875). The Australian specimens are considerably smaller
than those found in Europe and America, they may further be distinguished
by the length of the root in proportion to the size of the crown; and whilst
the Zeuglodonts of America have the roots divided into two widely-separated
fangs, equalling in depth the height of the crown, those of Australia resemble
Squalodon grateloupi in having the root single, and only marked by a median
vertical sulcus ascending to the base of the crown. The specimen from the
Oamaru formation of New Zealand possesses characters which appear to render
necessary its location as a distinct species.

Squalodon serratus, Davis.
(PI. vii., fig. 9.)

This species is represented by a single tooth from the White Rock River
Quarry. It is enveloped in a matrix of light-coloured calcareous sandstone. The
crown only is exposed, and consists of a number of cones, of which six are visible,
having obtusely-pointed apices. The root, if present, is hidden in the matrix.
The base of the crown, so far as exposed, is 0'8 inch in breadth ; the central and
most prominent cone rises to a height of 0*75 inch ; it is erect, convex, depressed
towards the margin, which is thin and slightly crenulated. Four other denticles
extend from the central one on the left side, diminishing in height and size as they
recede ; they are similar in form to the median one, except that they exhibit a
tendency to incline towards it. On the opposite side only one denticle is exposed :
it corresponds in form and size to the first denticle to the left of the median one.
The specimen has been exposed by cutting away the matrix as far as it appears
safe to proceed. The enamel is so fragile that to attempt to work further would
probably result in the entire breaking-up of its surface and the ruin of the speci-
men. There appears every probability, however, that if the tooth were fully
exposed it would be found that a series of secondary denticles would extend on the
right side of the central one, more or less similar to those on the left. The surface
of the crown is ornamented by a rugose network of striations, coarse towards the
base, becoming finer towards the summit, and gradually disappearing near the
margin.

This fossil tooth presents a certain resemblance to those of the family of
Gymnodonts, comprising the existing marine genera Tetrodon and Diodon, and

Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand. 47

represented in a fossil state in the Tertiary Limestones of Monte Bolca and Licata
by the genus Diodon, and by a second genus Enneodon, from the Tertiary beds of
Monte Postale. The existing genera comprise about seventeen species, inhabiting
the tropical parts of the Atlantic and Pacific seas. Tetrodon is characterized by
having a dental arrangement, consisting of a plate attached to each ramus of the
two jaws, divided by median sutures, whilst Diodon has only a single undivided
dental palate to each jaw. It consists of a semicircular plate, extending backwards
into the mouth, in the form of a palate, the front edge is slightly produced and
somewhat beak-like, the teeth also encircle the jaw and extend along its outer
surface. This dental arrangement is admirably adapted to break up masses of
coral or the hard shells of molluscs and crustaceans on which the fishes feed.

In considering the relationship of this peculiar tooth, its series of denticles
suggests an affinity with Notidanus. In the latter, a more or less extended root
supports a number of conical denticles, the anterior one being, as a rule, the
largest, followed posteriorly by others similar in form, but diminishing in size as
they recede from the principal one; the whole are inclined, with considerable
obliquity, backwards. In this specimen the princijDal cone is erect, and occupies
a median position, with a number of denticles on each side, the latter diminish in
size as they recede from the centre like Notidanus ; but instead of being inclined
obliquely from the principal cone they bend over towards it. The circumstance
of the secondary denticles extending from both sides of the principal one sufficiently
asserts the difference between the two.

The specimen now described is, in many respects, similar to those of the
existing Diodons: it differs from them in others. The surface exposed is the
outer one, and its series of denticles, rising from an undivided base, apparently
without a root, closely approximate to that of Diodon ; but whereas the latter is
undivided quite to the cutting-edge, this species is so deeply serrated as to form a
series of large and prominent denticles. In this respect it resembles to a remark-
able degree the teeth of Pristodus falcatus (" Trans. Royal Dublin Society," vol. i.,
ser. 2, p. 519, pi. lxl, figs. 17—22). These latter were obtained from the upper-
most beds of the mountain limestone series of Yorkshire. The tooth of the upper
jaw is semicircular in outline, diminishing in height posteriorly, and its denticu-
lated cutting-edge extended obliquely forwards, from above downwards. The
lower jaw was enveloped in a similar bony investment; the median portion of
the tooth is produced to form a beak-like prominence, the remaining portion of
the crown surface being smooth and even.

Notwithstanding the external resemblance of the tooth now described to those
of Pristodus, it appears to possess still greater relationship with the genus
Squalodon found in the Miocene beds of Victoria. Squalodon zvilkinsoni (M'Coy),
{op. cit.), slightly exceeds 2*5 inches in height, of which the crown occupies 075
inch ; its breadth is under 1*0 inch. The median denticle is large in proportion

48 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

to the lateral ones ; of tlie latter there are two denticles on the anterior surface,
and three on the posterior one. The latter denticles diminish rapidly in size, and
the surface is marked with coarse, rough, irregular sulci. The New Zealand
species closely resembles that described by M'Coy, in the form of the median
denticle and the surface-markings ; it differs in the number of lateral denticles,
or cones, and also in the convex outer margin of the crown ; for whilst it is curved
from the median denticle backwards the Australian specimen is nearly straight.
The imperfection of the tooth renders its identification a little difficult; but the
balance of its several characters appears to indicate its relationship with the genus
Squalodon rather than with Pristodus, and it is proposed to include it, provi-
sionally, in that genus, with the specific appellation, serratus.

Formation. — Oamaru formation.

Locality. — White Rock River Quarry, New Zealand.

Ex coll. — Canterbury Museum, Christchurch.

LIST OF SPECIES, WITH THE LC

List of Species
and

Reference to Pages.

0

O

cd
bo
n3

O

O

o

CD

3
Q

CD .?H

cd ,3

&< a

cd rn

e3
o3 3

fH CO

(jrdleOCei&O dCUloduUb, x/avio,

p. 8

X

X

n^/l /mi q v> rvn af i/1 Plici A f/aSSlZ ■

(Jarcnarocioii aiigu&iiuciia, ag^^j

„ 9

X

X

X

X

(J megaiotioii, xi^ciooi^j

„ 12

lODUSTjUa, lydvio,

„ 13

Ofnrlnc; nKlifmilS A^assiz, ...

„15

LnmriQ lm+frmi T)fliVlS.

,,'15

X

incur vd, j-/civio, ••«

„17

X

X

X

cm aimil P f P DaVlS. ...

„18

Hiaiglliailb, .L/aiYio, ...

„ 19

X

r» + J- /Ml unto l) P VI

atbGilUaia, XJchyiOf

„ 19

X

lanceoiaijd, i/divioj •■•

„20

X

X

carinata, Davis,

>. 21

7 7

X

1 vpvhp ni'fP I

„21

X

M iiecTjori, x/dvio) •••

„21

(~\A mi-fa cm a Q PIT t.P, 1 /RjVIS . . ■ •

,,22

X

i-\ vi n*n a TlP VI
f( BXlgUdj i/CLVlO, ...

,,23

X

X

„24

X

J? bUlL-tA Id, J-/ CIV AO, •••

„ 25

Uxyinma von iiddDuii, x/ojvj.0,

„26

16Cld, -L/dVlb,

„27

X

enysn, jUdvis,

,, 28

„29

X

rrvpnrli Q DrVIK.

?( tJlctllU.l&, _L/ Cm \ ±J } •••

„30

X

iasiigiatd, j^dvi»,...

,, 30

X

_ SUDVeXd, UdM-o, •••

,, 31

1p+p T)n,vis

j ( la Ul , j_/c* via,

„32

XTMirlpnna. TiVimio'eniuS* A^dSSlZ,

„ 33

X

m o TfTi i"i fil i ^ "Davis .

„34

X

dentatus, S.-Woodw.,

,, 36

Trygon ensifer, Davis,

,, 37

X

x

Myliobatis plicatilis, Davis,

,,39

X

X

X

arcuatus, Davis,...

„40

X

,, altus, Davis,

,,40

Callorbyncbus bectori, Newton,

„41

...

Iscbyodus brevirostris, Agassiz,

,,42

Bargus laticonus, Da^s,

„43

X

X

Squalodon serratus, Davis,...

„46

CD

c3
O

'3

9

3

° «

S3

CP

a

G

O

o

a

c3

> 3

a

eg O

o

TRANS. ROY. DUB. SOC, N.S. VOL. IV.,

PACT I.

UTIES IN WHICH THEY OCCUR.

EXPLANATION OF PLATE I.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART I. H

50 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

PLATE I .

Figs. 1-3, Galeocerdo aculeatus. Davis.

1. Posterior tooth. a. External surface. b. Internal surface. c. Side view.

la. Magnified 3 diameters.

2. Anterior tooth. a. External surface. b. Internal surface.

3. Small posterior tooth.

Coleridge Gully, . . . .Ex coll. Canterbury Museum, Christchurch.

Figs. 4-6, Caecharodon angustidens. Agassiz.

4. Posterior tooth. a. External surface. b. Internal surface. c. Side view.

5. Anterior tooth. Internal surface.

6. Another specimen. Internal surface.

4. Waihoa Forks, .... Ex coll. Canterbury Museum, Christchurch.

5. Otago, . . . . .Ex coll. Otago Museum.

6. Wekapass, .... Ex coll. Canterbury Museum, Christchurch.

Fig. 7,

Carcharodon robustus. Davis.

a. External surface. b. Internal surface. c. Side view.
Waitaki, . . . . .Ex coll. A. M'Kay, Otago Museum.

Trans . R . Dub. S ., N. S .Vol . IV.

Plate 1.

EXPLANATION OF PLATE II.

H2

52 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

PLATE II.

Fig. 1, Carcharodon megalodon. Agassiz.

u. External surface. b. Internal surface. c. Side view.
Cape Foulwind, Nelson, . Ex coll. "Wellington Museum.

Fig. 2, Carcharodon megalodon. Agassiz.

a. External surface. b. Internal surface. c. Side view.
Wekapass, . . . Ex coll. Canterbury Museum, Christchurch.

Fig. 3, Carcharodon megalodon. Agassiz.

Near Bobby's Creek, . . Ex coll. Geological Survey Collections Wellington Museum.

Trans . R.Dab. S ,N. S.,Vol.IV.

Plate II,

J W.Dasis dtrmt. W.H Cronther del.

Mmlern Br03 . imp

54 Davis — On Fossil-Fish Remains from the Tertiary Formations of Neiv Zealand.

PLATE III.

Fig. 1, . . Lamna huttoni. Davis.

a. External surface. b. Internal surface. c. Side view.
Cave Valley, Oamara, . . .Ex coll. Professor F. W. Hutton.

Figs. 2-5, . Lamna incurva. Davis.

2 a. External surface. 2b. Internal surface. 2c. Side view.
2. Kaikoura. 8. Coleridge Gully. 4. Curiosity Shop Beds.

Ex coll. Canterbury Museum, Christchurch.

Figs. 6, 7, . Lamna ensiculata. Davis.

6. External surface.

la. Internal surface. lb. External surface. 1 c. Side view.
Oamaru, .... Ex coll. Canterbury Museum, Christchurch.

Figs. 8-10, . Lamna marginalis. Davis.

a. External surface. b. Internal surface. c. Side view.
Broken Biver, .... Ex coll. Cambridge Museum, Christchurch.

Fig. 11, . Lamna attenuata. Davis ( x 3 diameters).

a. External surface. b. Internal surface. c. Side view.
Coleridge Gully, . . . Ex coll. Canterbury Museum, Christchurch.

Fig. 12, . Lamna lanceolata. Davis.

a. External surface. b. Internal surface. c. Side view. d. Under surface.
Castle Hill Station, Canterbury, . . Ex coll. J. Davies Enys.

Fig. 13, . Lamna caeinata. Davis.

a. External surface. b. Internal surface. c. Side view.
Kaikoura Peninsula, . . . Ex coll. H. J. Ingles, Otago Museum.

Figs. 14, 15, Lamna sp. ? Vertebrae.

Awamoke and Kaikoura, . Ex coll. B. Gillies ; T. J. Parker, Otago Museum.

Fig. 16, . Lamna hectori. Davis.

West Wing Amuri Bluff, . Ex coll. Sir J. Hector, Geological Survey Collections

Trans . R . Dull . S .. N . S.,Vol . IV.

Plato 111.

J-W Dbots diradt W H Crowther U

Mjritem Brcxs ux.p

EXPLANATION OF PLATE IV.

56 Davis — On Fossil- Fish Remains from the Tertiary Formations of New Zealand.

PLATE IV.

Figs. 1-3, Oxyehina von haastii. Davis.

1. Mass of detached teeth, probably belonging to one fish.

2. Detached tooth. a. Internal surface. b. External surface. c. Side view.

3. Another specimen.

1 and 2. Oamaru, . . Ex coll. Cambridge Museum, Christchurch.

3. Bobby's Creek, . . Ex coll. Geological Survey Collections, Wellington Museum

EXPLANATION OF PLATE V.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART I. I

58 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

PLATE V.

Figs. 1,2, . Odontaspis acuta. Davis.

a. External surface. b. Internal surface. c. Bide view.

1. Curiosity Shop Beds. . . . Ex cull. Canterbury Museum, Christchurch.

2. Trelissic, near Canterbury. . . Ex coll. Wellington Museum.

Figs. 3, 4, 5, Odontaspis exigua. Davis.

'da. External surface. 'Ab. Side view. 4. Posterior tooth. 4rt. Same, en-
larged. 5. Anterior tooth. 5«. Same, enlarged.

3. Castle Hill Station, near Canterbury, . Ex coll. J. Davies Enys.

4. 5. Broken Biver, . . . Ex coll. Canterbury Museum.

Figs. 6-10, . Odontaspis kaikoraensis. Davis.

6<i. Internal surface. 6b. Side view. 7, 8, 9. External surface of other
specimens. 10. Similar to 6, with much shorter root.
6. Kaikoura, .... Ex coll. J. Davies Enys.
7-10. Eastwing, Amuri Bluff, . Ex coll. Wellington Museum.

Figs. 11-13, Odontaspis sulcata. Davis.

11 a. Enlarged. 13. Surface smoothed by abrasion.
All from Amuri Bluff, . . . Ex coll. Wellington Museum.

Fig. 14, . . Oxyrhina recta. Davis.

a. External surface. b. Internal surface. c. Side view.
Castle Hill Station, near Canterbury, . Ex coll. J. Davies Enys.

Figs. 15, 16, Oxyrhina grandis. Davis.

a. External surface. b. Internal surface. c. Side view.
Broken River, .... Ex coll. Canterbury Museum, Christchurch.

Figs. 17-20, Oxyrhina enysii. Davis.

a. External surface. b. Internal surface. c Side view.
Waipara, ..... Ex coll. Canterbury Museum, Christchurch.

Fig. 21, . Oxyrhina acuminata. Davis.

a. External surface. b. Internal surface. c. Side view.
Castle Hill Station, near Canterbury, . Ex coll. J. Davies Enys.

Trans. R.Dub. S,N. 5 ..Vol. IV.

Plate V.

J WDa.v.s.du-out W.H.CiWW,<Ul.

M intern Bros . imp

EXPLANATION OF PLATE VI.

I 2

GO Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

PLATE VI.

FigS. 1-3, . OxYRHINA FASTIGIATA. Davis.

la. External surface. lb. Internal surface. lc. Side view.
2. Anterior tooth. 3. Posterior tooth.

Coleridge Gully, .... Ex coll. Canterbury Museum, Christchurch.

Fig. 4, . . Oxyrhina subvexa. Davis.

a. External surface. b. Internal surface. c. Side view.
Oamaru, . . ... . Ex coll. J. Davies Enys.

Fig. 5, . . Oxyrhina lata. Davis.

Kakahu Kiver, South Canterbury, . Ex coll. Professor T. J. Parker, Otago.

Fig. 6, . . Notidanus primigenius. Agass. (Upper jaw).

Cave Valley, Oamaru, . . . Ex coll. Professor F. W. Hutton, Otago.

Figs. 7, 8, . Notidanus marginalis. Davis.

7. (Upper jaw), a. External surface. h. Internal surface. c. Side view.

8. (Lower jaw), a. External surface. b. Internal surface. c. Side view.
Castle Hill Station, . . . Ex coll. J. Davies Enys.

Figs. 9-12, . Notidanus dentatus. A. Smith-Woodward.

9. Tooth from upper jaw. 10. Tooth from lower jaw.

Amuri Bluff, . . Ex coll. Natural History Department, British Museum.

11 and 12. Teeth, lower jaw.
Amuri Bluff, Waireka series. Ex coll. Geological Survey Collection, Wellington.

Figs. 13-15, Trigon ensifer. Davis.

13. Teeth, a. Median tooth, enlarged. b. Lateral tooth, enlarged.
Coleridge Gully, . . . .Ex coll. Canterbury Museum, Christchurch.

14. Spine, 14«. Same, enlarged.

Waipara, .... Ex coll. Canterbury Museum, Christchurch.

15. Spine, another example. 15a. Enlarged.

Amuri Limestone, Amuri Bluff. . Ex coll. Geological Survey Collections, Wellington.

Figs. 16-19, Myliobatis plicatilis. Davis.

a. Upper surface. b. Under surface. c. Side view.
16, 17, Castle Hill Station, . . Ex coll. J. Davies Enys.

18, 19, . . . . Ex coll. Canterbury Museum, Christchurch.

Figs. 20,21. Myliobatis arcuatus. Davis.

a. Upper surface. b. Under surface. c. Side view.

20, ..... Ex coll. Canterbury Museum, Christchurch.

21. Castle Hill Station, . . . Ex coll. J. Davies Enys.

Fig. 22, . Carcharodon angustidens. Agass. (young example).

Napier Series, Esk Kiver, Hawkes' Bay, . Ex coll. Sir James Hector, M.D., Geological

Survey Collections.

Trans. R.Dub. S.,N. S., Vol . IV.

Plate VI.

.WSaws du^at W.H.Crowther del.

Minteni Bros imp.

EXPLANATION OF PLATE VII.

62 Davis — On Fossil-Fish Remains from the Tertiary Formations of New Zealand.

PLATE VII.

Figs. 1,2, . Myliobatis altus. Davis.

la. Upper surface. b. Under surface. c. Side view.
2. Median part of another tooth.
Broken Eiver, . . Ex coll. Canterbury Museum, Christchurch.

Figs. 3-7, . Sargus laticonus. Davis.

Coleridge Gully, . . Ex coll. Canterbury Museum, Christchurch.

Fig. 8, . Otoliths ? Sargus.

a. Upper surface. b. Lower surface. c. Side view.
Coleridge Gully, . . Ex coll. Canterbury Museum, Christchurch.

Fig. 9, . Squalodon sereatus. Davis.

Whiterock Eiver Quarry, . Ex coll. Canterbury Museum, Christchurch.

Fig. 10, . Ischyodus brevirostris. Agassiz.
Eight mandible.

Amuri Bluff, . . . Ex coll. Natural History Department, British Museum.

Figs. 11-13, Ischyodus brevirostris. Agassiz.

11 and 12. Under surface of a jaw.
13. Upper surface of a jaw.
Amuri Bluff, . . . Ex coll. Geological Survey Collections, Wellington.

Fig. 14, . Callorhynchus hectori. Smith- Woodward.

Amuri Bluff, . . . Ex coll. Natural History Department, British Museum.

Fig. 15, . Callorhynchus hectori. Smith-Woodward.

a. Upper surface. b. Under surface of jaw.
Eastwing Amuri Bluff, . Ex coll. Geological Survey Collections, Wellington.

Fig. 16,

Otodus obliquus.
Amuri Bluff, .

Agassiz.

Ex coll. Geological Survey Collections, Wellington.

Trans. R. DuV>. S., N. S., Vol. IV.

Plate VII.

W Davis iracil.'W.H CrowtW del.

Mmtern Bros imp.

[ 63 ]

II.

A MONOGRAPH OF THE MAEINE AND FRESHWATER OSTRACODA OF
THE NORTH ATLANTIC AND OF NORTH - WESTERN EUROPE.
Section I. PODOCOPA. By GEORGE STEWARDSON BRADY, M. D.,
F.R.S., F.L.S., and the REV. ALFRED M. NORMAN, M.A., D.C.L., F.L.S.
Plates YIII. to XXIII.

(Communicated by Professor Haddon.)
[Read March, 1888.]

We propose to include in this memoir all the species of Podocopa known to us as
inhabiting the Arctic Seas, the North Atlantic Ocean, and North- Western Europe.
We have regarded the North Atlantic as terminating at 35° N., thus excluding the
tropical species of the West Indies and Gulf of Mexico. The Mediterranean is
not included, as a consideration of all the forms belonging to that area would
have too greatly extended our work. In North-Western Europe we embrace
Scandinavia, Denmark, Holland, Belgium, Germany, Austria, France, and the
British Islands.

The marine species of Norway have been studied by Professor G. O. Sars and
Dr. Norman; those of Sweden by Professor Lilljeborg. Little has been done
with respect to the marine species of Denmark and Germany since the time of 0.
F. Muller, except that a few species have been carefully investigated by Dr. Zenker
and Dr. Wilh. Muller. Our knowledge of Dutch marine Ostracoda has been derived
from the examination by Dr. Brady of material dredged by Mr. E. C. Davison in
the rivers Maas and Scheldt. The Ostracoda of the coasts of Belgium and France
have not been studied, except that a large number of interesting forms have
rewarded the investigations of the Marquis de Folin, and Dr. Norman in the Fosse
de Cap Breton in the Bay of Biscay. The expeditions of the British Government,
in H. M. SS. Porcupine, Lightning, and Triton, have afforded valuable material with
respect to the Ostracodan fauna of the depths of the Atlantic. With the exception
of Greenlandic forms, which are known to us from mud and sand procured from
whalers, from the dredgings of Dr. Sutherland, and from the expedition of the

TKAXS. EOT. DTJB. SOC, N.8. VOL. IV. PAET IT.

K

61 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Alert, Discover?/, and Valorous, little is known of truly Arctic species. The Ostracoda
of the American side of the Atlantic have not been studied, and our endeavours to
procure material from that portion of the area have hitherto failed. A few species
from the Gulf of St. Lawrence were described, some years ago, by Dr. Brady, but
nothing- whatever is known of the species which inhabit the coasts of the United
States.

The freshwater Ostracoda have been more or less studied in Norway by G. 0.
Sars; in Sweden by Lilljeborg; in Denmark by no one since the time of 0. F.
Miiller ; in Holland not at all ; in Belgium by Plateau ; in Germany by Koch,
Zaddach, and Willi. Miiller; and a few species have also been kindly forwarded to
us by Herr Poppe ; in England by Baird, our old friend Mr. D. Robertson, Mr.
Scott, and ourselves. At the time when the MS. of this paper was sent to the
printer we knew absolutely nothing of the inland Ostracoda of France ; but these
are now being worked at by Professor R. Moniez, of Lille, who has published two
or three short but interesting Papers upon them.

The distribution of living sj:>ecies, as far as known, is briefly recorded, whether
within or beyond the district with which we are more immediately concerned ;
and the same method has been adopted with respect to species occurring in post-
tertiary deposits.

The present memoir, though embracing a larger area, is intended to supple-
ment the account of the British species given in " A Monograph of the recent British
Ostracoda," published by Professor G. S. Brady in the Transactions of the
Linnean Society (vol. xxvi., 1868). The species referred to in that work are
therefore not here re-described or figured, except in the few cases where it was
considered that the illustrations in the "Monograph" were scarcely sufficient to
distinguish the species from more recently discovered forms.

For the same reason the synonymic references given in that "Monograph" will
not be found here, though we have thought it convenient briefly to mention such
synonyms ; so that in these pages the full synonymy may be found, without an
undue repetition of references. A list of the principal Works and Papers on the
Ostracoda of the area embraced in this memoir is given at the end.

Without the kindly co-operation of many others, this work must have been far
less complete than we have now been able to make it.

Mr. D. Robertson has most kindly placed his very extensive collection of
Ostracoda, including some und escribed forms, at our disposal ; and we are
indebted to Mr. T. Scott and the late Dr. Malcolmson for the communication
of new or interesting forms.

To our ever kind friend, Professor G. 0. Sars, of Christiania, we are greatly
indebted for much valuable help. Not only has he supplied us with specimens of
many Norwegian species described by himself and otherwise unattainable, but,

of the North Atlantic and North -Western Europe.

65

when unable to send specimens, has most liberally given us outline drawings for
reproduction in our illustrations.

Professor Seeliger of Konigsberg has rendered valuable assistance to the
cause of science in generously entrusting to our care the types of Zaddach's
species preserved in the Museum of that town, and thus synonymy has been
rectified in a way which could not otherwise have been done.

Our sincere thanks for the communication of specimens and information are
also due to Professor Lilljeborg of Upsala, Dr. Wilhelm Mttller of Greifswald,
Herr Poppe of Vegesack, Professor Moniez of Lille, Professor Orley of Budapest,
and Professor Heller of Innsbruck.

Lastly, we owe much to the kindness of our friend, the Marquis de Folin,
who has not only placed at our disposal many Ostracoda dredged by himself
in his important investigations in the Fosse de Cap Breton, but also some highly
interesting Myodocopa procured from great depths by the French expeditions of
the Travailleur and Talisman.

The mark (!) after a locality indicates that we have identified specimens from
that place, or the types of the author after whose name it is placed.

OSTRACODA.
Section I. — Podocopa.

Fam. I. — CYPRIDIDiE.

Shell generally thin and horny ; valves equal or but slightly unequal in
size, surface usually smooth, or simply punctated ; ventral margins more or
less sinuated ; hinge margins edentulous. Eyes simple, usually confluent, some-
times wanting. Antennules (first antennae) slender, usually seven-jointed, very
flexile, usually provided with a number of long hairs forming a dense brush.
Antennas (second antennae) pediform, geniculated, four- or five- jointed, clawed
at the apex, second joint mostly bearing an apical brush of hairs. Mandibles
strong, apex strongly toothed, palp four- jointed, with a setiferous branchial
plate at the base. Two pairs of maxillae, the first pair four-digitate ; its external
branch distinctly two-jointed, bearing a large setiferous branchial plate ; second
pair small, composed of a single prehensile lobe and a palp, which in the female is

K 2

66 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

generally simple, rarely pediform, is in the male prehensile. Two pairs of feet
dissimilar in structure, the anterior pair strong, ambulatory, directed downwards,
and having a long curved apical claw; posterior bent backwards within the shell,
and not used for motion. Caudal rami usually well developed, elongated, very
mobile, and bearing two or three apical claws. Intestine forming two dilatations, of
which the anterior is provided with ccecal appendages. Generative organs large,
and of complex structure, and partly extended within the valves ; in the male
frequently a complex whorled sac (? ejaculatory organ) connected with the
testis; copulatory organs symmetrical, and of moderate size.

Fam. II. — BAIRDIIDiE.

Shell generally hard and calcareous, valves unequal, surface smooth, hinge
toothless. No eyes. Antennules scarcely geniculated, seven- jointed; first two joints
elongated, the rest very short, but beset with long hairs. Antennas pediform,
five-jointed, clawed, but destitute of a setose brush. Mandibles large ; biting ex-
tremity incurved, and strongly toothed ; palp well developed ; branchial appendage
small, and bearing only a few non-ciliated setae. First pair of maxillae only
adapted for mastication ; second pair, as well as the two following pairs of
appendages, ambulatory, pediform, and directed downwards. Two pairs of
branchial plates, one attached to the first, the other to the second pair of maxillae.
Caudal rami well developed, though not large ; linear, clawed. Ovaria and testes
not extended within the valves ; whorled sac wanting. Copulative organs of the
male moderately large and complex. Animal not adapted for swimming.

We follow Professor G. O. Sars in dividing the old group, Cyprididae, into two
families, Cyprididae and Bairdiidae, the chief points of distinction being found in
the structure of the second and fourth pair of " post-oral appendages" (second
maxillae and second pair of feet) ; also in the absence of a whorled sac in the
males of the Bairdiidae, and in their very unequally-valved shell.

Fam. III.— DARWINULID^.

Autennae destitute of swimming setae and of poison gland and duct. Mandible-
palp three-jointed ; the basal joint large and densely setiferous. Two pairs of
jaws, the first bearing a large branchial plate, the second a smaller branchial plate
and a pediform palp. Two pairs of feet external to the valves. Post-abdominal lobes
sub-conical, small.

of the North Atlantic and North- Western Europe.

67

Fam. IV. — CYTHERIDiE.

" Shell mostly hard, calcareous, usually with an uneven surface, either sparingly
clothed with hairs or altogether bare; hinge generally toothed. Eyes more or less
separated, sometimes wanting. Antennules sub-pediform, geniculate at the base;
five- to seven- jointed ; beset with short setae, which are partly spine-like. Antennae
strong, pediform, curved, four- or five- jointed, with two terminal claws; basal
joint bearing a long setiform, biarticulate flagellum, which conveys a duct from a
poison-gland; second joint destitute of a setose brush. Mandibles usually strong,
enlarged and toothed at the apex ; palp well developed, directed forwards, and
bearing on the posterior margin strong, curved setae, and a poorly-developed
branchial appendage. First pair of post-oral appendages more or less maxilliform ;
three following alike, pediform, directed downwards, adapted for walking. One
pair of branchial laminae attached to the maxillae. Caudal rami obsolete, forming
two rounded, setiferous lobes; copulatory organs of the male large and complex :
in addition to which there is a curious bifurcate appendage between the feet of
the first pair; ovaria and testes not produced between the valves; no mucous
gland. Animal incapable of swimming." (G. O. Sars.)

Fam. V.— PARADOXOSTOMATID^E.

Shell thin and fragile, smooth ; contact margins imperfectly closed in front,
allowing of the protrusion of the mandibles. Poison glands large; noti eating setae
large and stout. Mandibles slender and styliform, adapted for piercing, enclosed
in a suctorial sheath formed by the coalesced labrum and labium ; palp without
a branchial appendage. First pair of maxillae bearing a branchial plate, which is
provided with two setae.

68 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Fam. I. — CYPRIDIDiE.

Genus I. — Cypria, Zenker.

Limbs longer and more slender than in Cypris ; swimming setse of the antennae
few (usually five) in number, and of great length. Apical joint of the mandible-
palp very long and slender. Principal apical seta of the second foot very long —
about as long as the entire limb. In the male the second pair of jaws is prehensile
and somewhat different on the two sides (right and left) ; the whorled sac is
cylindrical, and bears seven whorls of filaments, the two terminal whorls chitinous,
rigid, and composed of few (seventeen) ; the other five of very numerous and fine
filaments; the upper extremity of the organ forms a dilated blind pouch, the lower
(distal) extremity forming a funnel-shaped sac, which leads into the vas deferens;
copulative organs of moderate size. Zoosperms longer and more slender than in
Cypris ; arranged in two compact coils over the back of the animal. Eyes large,
not widely separated, united at the base ; ovarian tubes of female having a double
curve.

[Type. — Cypria exsculpta (Fischer) = C. punctata, var. striata, Zenker.]
The species of Cypria are all small, and ovate or reniform in outline. They
form two groups, one containing C. exsculpta and C. ophthalmica, in which the valves
are sub-compressed, the other embracing the remaining forms, which are all very
tumid.

1. Cypria exsculpta (S. Fischer).
'(Plate xi., figs. 1-4.)

1853. Cypris elegantula, Lilljeborg, De Crust, ex ord. tribus, p. 206 (non C. elegantula, Fischer).

1854. Cypris exsculpta, Fischer, Beitrag zur Kenntniss der Ostracoden, p. 18, pi. xix., figs. 36-38.
1854. Cypria punctata, var. striata, Zenker, Monog. der Ostracoden, Archiv fur Naturgeschichte,

p. 77, pi. iii., figs. 1-6.
1868. Cypris striolata, Brady, Mon. rec. Brit. Ostrac, p. 372, pi. xxiv., figs. 6-10.
1880. Cypris granulata, Robertson, Fresh and Brackish Water Ostracoda of Clydesdale, p. 18 (junior.)

Additional localities. — This is a widely-distributed species, and has been met
with in many localities in the East Anglian district (G. S. B. & D. R.) : Osmere, near
Whitchurch, Shropshire (G. S. B.) : at Lochmaben ; Cumbrae ; Upper Braide,
Farne Loch, Edinburgh ; Possil Marsh, Glasgow ; and canal at Peterhead ; in lochs
near Dumfries, and in the Isle of Lewis (D. R.) ; at Hairmyres, near East Kilbride;

of the North Atlantic and North-Western Europe.

69

in moor tarns at Glenluce, and in Whitefield Loch, Wigtonshire ; Loch Aber,
Kircudbrightshire ; Newbiggin, Northumberland ; Seaton Carew, Co. Durham ; and
Kibworth, Leicestershire (A. M. N.)

Distribution. — Sweden (Lilljeborg !) ; Prussia (Zenker); Russia (S. Fischer);
France (Moniez).

2. Cypria ophthalmica (Jurine).
(Plate xi., figs. 5-9.)

1820. Monoculus ophthalmicus, Jurine, Hist, des Monocles, p. 178, pi. xix., figs. 16, 17.

1838. (?) Cypris punctata, Koch, Deutschl. Crustac, H. 21, p. 23, fig. 23 (non C. punctata, Jurine).

1837. Cypris tenera, idem, ibidem, H. 12, p. 3.

1835. Cypris compressa, Baird, Trans. Berw. Nat. Club, vol. i., p. 100, pi. iii., fig. 16.

1851. Cypris elegantula, Fischer, Ueber das Genus Cypris, p. 161, pi. x., figs. 12, 13.

1868. Cypris compressa, Brady, Mon. rec. Brit. Ostrac, p. 372, pi. xxiv., figs. 1-5 ; pi. xxxvi., fig. 6.

1872. Cypris ovum, Fric, Die Krustenthiere Bohmens, p. 228.

1875. Cypris compressa, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 123, pi. i., figs. 5, 6.

One of the commonest of British species, occurring everywhere in ditches,
ponds, and lakes, both freshwater and brackish.

Distribution. — Norway (G. O. Sars); Sweden (Lilljeborg!); Belgium (Plateau);
Germany (Koch and Wilh. Miiller); Geneva (Jurine); Russia (S. Fischer);
Bohemia (Fric); France (Moniez), also recorded by him as C. Joanna ; Transyl-
vania (Daday).

Fossil. — England, Scotland.

3. Cypria Icevis (0. F. Miiller).

1785. Cypris lavis, Miiller, Entom., p. 52, pi. iii., figs. 7-9.

1820. Monoculus ovum, Jurine, Hist, des Monocles, p. 179, pi. xix., figs. 18, 19.

1835. Cypris minuta, Baird, Trans. Berw. Nat. Club, i., p. 99, pi. hi., fig. 9 ;

and Brit. Entom., p. 155, pi. xviii., figs. 7, 8.
1837. Cypris hrunnea and lepidula, Koch, Deutschlands Crustaceen, H. x., 5 and 6.
1844. Cypris vulgaris, {ZaMach, Syn. Crust. Pruss. Prod., p. 35.

1851. Cypris pantherina, Fischer, Abhandl. fiber das Genus Cypris, p. 163, pi. xi., figs. 6-8.
1853. Cypris ovum, Lilljeborg, De Crust, ex ord. tribus, p. 113, pi. x., figs. 13-15.

1868. Cypris ovum, Brady, Mon. rec. Brit. Ostrac, p. 373, pi. xxiv., figs. 31-34, 43-45 ; and
pi. xxxvi., fig. 8.

1868. Cypris ovum, Claus, Beitrage zur Kenntniss der Ostracoden, Entwicklungsgeschichte von
Cypris, pi. i., figs. 1-5.

1874. Cypj-is ovum, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 125, pi. i., figs. 29-31.
Common in Great Britain and Ireland, in fresh and brackish water.

70

Brady and Norman

— Monograph of the Marine and Freshivater Ostracoda

Distribution. — Norway (Sars); Sweden (Lilljeborg !); North Germany ! (Poppe);
Denmark (Miiller) ; Belgium (Plateau) ; France (Moniez) ; Prussia (Zaddach !) ;
Switzerland ( Jurine) ; Russia (Fischer) ; Hungary (Orley) ; Finland (Cajander) ;
Transylvania (Daday).

Fossil. — England, South Wales (Cardiff) ; var. ? Sicily (Seguenza).

There is great difficulty in disentangling the synonymy of this and the following
species. The colouring of Koch's figures of C. brunnea and C. lepidula is very
characteristic of this species, though the outline, as seen from above, is represented
as much too tumid.

4. Cypria serena (Koch).

1838. Cypris serena, Koch, Deutschlands Crustaceen, H. xxi., 22.
1838. Cypris fuseata, Koch, id., ibid., H. xxi., 21.

1844. (?) Cypris rubida, Zaddach, Synops. Crust. Prussic. Prod., p. 36.

1851. Cypris scutigera, Fischer, Abhandl. iiber das Genus Cypris, p. 162, pi. xi., figs. 3-5.

1854. Cypria ovum, Zenker, Monog. der Ostracoden, p. 79, pi. iii. b.

1868. Cypris lavis Brady, Mon. rec. Brit. Ostrac, p. 374, pi. xxiv., figs. 6-8.

1874. Cypris lavis, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 126, pi. i., figs. 25-28.

1874. Cypris ovum, Heller, Unters. fiber die Crustaceen Tirols, p. 89.

1880. Cypris ovum, Willi. Miiller, Zeitsch. fiir gesarnmt. Naturwiss., vol. vi., p. 221, pi. iv., fig. 11.
Common in ditches, slow streams, and lakes.

Distribution. — Norway (Sars); Sweden (Lilljeborg !) ; Belgium (Plateau);
France (Moniez) ; Prussia (Zaddach) ; Pomerania (Willi. Miiller !) ; Tyrol (Heller) ;
Hungary (Orley); North Germany (Poppe!).

Fossil. — Scotland, England.

No specimens of C. rubida exist in Zaddach's collection.

5. Cypria joanna (Baird).

1868. Cypris joanna, Brady, Mon. rec. Brit. Ostrac, p. 375.
This species is unknown to us.

Genus II. — Cyclocypris, n. g.
(KukAos, a circle.)

Like Cypria , except in the structure of the mandible — which has the terminal
joint of the palp short — and the whorled sac of the male, the whorls of which are
composed of very numerous and excessively fine and long filaments ; the extremities
of the cylinder are not dilated, nor are they provided with circlets of stout setae,
as in Cypria, nor is there any distinct central axis; the whole organ is enveloped in
a capacious capsule.

of the North Atlantic and North -Western Europe.

71

Cyclocypris globosa (G. O. Sars).

(Plate xiv., figs. 1, 2; Plate xi., figs. 10-18.)
1844. (?) Cypris incana, Zaddach, Syn. Crust. Pruss. Prod., p. 33.

1863. Cypris globosa, G. 0. Sars, Om en i Sommeren 1862 foretagen Zoologisk Reise i Christianias

og Trondhjems Stifter, p. 27.
1868. Cypris cinerea, Brady, Mon. rec. Brit. Ostrac, p. 374, pi. xxiv., figs. 39-42 ; pi. xxxvi., fig. 7.
1874. Cypris cinerea, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 126, pi. ii., figs. 6, 7.

Shell of the male very tumid; seen laterally, ovate or sub-ovate ; highest near the
middle ; height equal to two-thirds of the length ; extremities rounded, the anterior
somewhat the narrower of the two ; dorsal margin gently arched in the middle,
sloping steeply behind, but more gradually towards the front ; ventral margin
almost straight. Seen from above, the outline is broadly ovate ; greatest width equal
to the height, and situated behind the middle ; broadly rounded behind, abruptly
tapered and subacuminate in front. Surface smooth and polished for the most
part, but on the ventral margin and at the extremities clothed with numerous short
hairs, intermingled with which are a few of excessive length ; at the posterior
ventral angle is a very dense growth of short hairs. Colour, brown, or yellowish-
brown, with darker cloudings. Length, 084 mm. The long seta3 of the antennae
are only two or three in number. Female unknown.

The specimens from which the description in the " Monograph of recent
British Ostracoda " was drawn up were immature, and the description and figures
consequently faulty. We have therefore here re-described the species from full-
grown examples.

Additional localities. — Isle of Lewis, and Lochmaben (D. R.) ; ditches by side of
Loch Ascog ; side of Greenan Loch ; and pools above high-water mark, West Loch
Tarbert (Mr. T. Scott): Broomley Lough, Northumberland (A.M.N.) : ditch near
Barlay Loch, Kirkcudbrightshire ; and pools at head of Easedale, Westmoreland
(G. S. B.) No specimens of C. incana exist in Zaddach's collection.

Distribution. — Norway (G. 0. Sars).

Fossil. — Scotland (Crofthead).

Ob

TRANS. EOY. DUB. SOC, N.S. VOL. IV., PART II.

L

72 Br\dy and Norman — Monograph of the Marine and Freshwater Ostracoda

Genus III. — Scottia, n. g.

Shell not unlike that of the tumid forms of Cypria. Setae of the antenna;
extremely short, not reaching even to the base of the claws. Whorled sac of the
male as in Cyprois. Limbs short arid stout; claws of the caudal rami very stout,
short, and twisted.

Scottia browniana (Jones).
(Plate ix., figs. 23, 24; Plate xi., figs. 19-25.)
1856. Cypris browniana, Jones, Mori. Tertiary Entom., p. 13, pi. i., figs. 1, a-d.

Shell short, high, and very tumid; seen laterally sub-ovate, highest behind the
middle ; height equal to more than half the length ; anterior extremity obliquely,
posterior more evenly rounded and broader ; dorsal margin forming a somewhat
flattened arch, the hinder slope steeper than that in front ; ventral margin only
slightly sinuated. Seen from above, broadly ovate, widest in the middle, breadth
equal to the height ; ends very broadly rounded, and nearly equal ; end view almost
circular. Surface smooth and polished, with a few scattered minute hairs, which are
only with difficulty seen ; shell pellucid, irregularly pencilled with dark markings ;
the brown colour of the animal also visible through the shell. Setose brush of the
antenna consisting of only three or four very short, simple hairs ; terminal claws
armed with a comb-like tuft of short, rigid seta?, extending over the middle of the
inner margin for about one-half of its length, and ending abruptly at each extremity.
The two claws of each caudal ramus are provided with a similar arrangement ; but
the tuft is not more than one-fourth of the length of the claw, and the secondary
marginal setae are only very finely pectinated. The second maxilla bears a
6-setose branchial plate, and, in the male, has a strongly-falcate claw. The first
pair of feet bear (instead of one) two long falcate ungues at the apex.

Mr. Thomas Scott has recently sent us this species, which he found in pools
near Loch Fadd, in the Island of Bute. Its occurrence in a recent state is of great
interest, as it has hitherto been known only from Professor Rupert Jones's
description of the fossil shell. We have pleasure in naming the genus after
Mr. Scott, in acknowledgment of his careful and industrious observations of marine
and freshwater invertebrata.

Fossil. — Clacton, in Essex (T. E. Jones).

of the North Atlantic and North- Western Europe.

73

Genus IV. — Cypkis, Miiller.
[Type, 0. pubera, Miiller.^
1. Cypris fuscata, Jurine.
(Plate xii., figs. 3, 4.)
Synonyms : C. hispida, Baird ; C. oblonga, Brady ; C. fusca, Baird, et auct. plur.

1820. Cypris fuscata, Jurine, Hist, des Monocles de Geneve, p. 174, pi. xix., figs. 1, 2.

1821. (?) Cypris fusca, Straus Durckheim, Mem. des Mus. d'Hist. Nat., vn., p. 59, pi. i., figs. 1-16.

1837. (?) Cypris adusta Koch, Deutsclilands Crustaceen, H. ii. 3.

1838. Cypris galbinea, Koch, Deutsclilands Crustaceen, H. xxi. 19 (junior).
1844. Cypris fuscata, Zaddach, Synopsis Crust. Prussicorum Prodromus, p. 32.

1853. Cypris fuscata, Lilljeborg, De Crust, ex ord. trib. Clad. Ostrac. et Coped, p. 114, pi. x., figs. 6-9 ;
pi. xii., fig. 5.

1868. Cypris fusca, Brady, Mon. rec. Brit. Ostrac, p. 362, pi. xxiii., figs. 10-15.
One of the most abundant British species.

Distribution. — Norway (G. O. Sars); Sweden (Lilljeborg!) ; Denmark (? Miiller);
Belgium (Plateau) ; Prussia (Zaddach !) ; Pomerania (Willi. Miiller !) ; Geneva
(Jurine); Tyrol (Heller); Bohemia (A. Fric) ; Hungary (Orley) ; Russia (S.
Fischer) ; Normandy (Moniez) ; Italy (Saccardo) ; Transylvania (Daday).

It is remarkable that, as far as we are aware, this common species has not yet
been found in a fossil state.

We think that there can be no doubt that Koch's C. galbinea represents the
young of this species. Types of Dr. Baird's Candona hispida are in Dr. Norman's
collection.

2. Cypris incongruens, Ramdohr.
(Plate xii., figs. 8, 9.)
Synonyms : M. ruber et aurantius, Jurine, et auct.
1844. Cypris aurantia, Zaddach, Syn. Crust. Pruss. Prod., p. 37.

1844. (?) Cypris ophthalma, Koch, Deutsclilands Crustaceen, &c, H. 36, p. 17 (junior).
1855. Cypris aurantia, S. Fischer, Beitrag zur Kenntniss der Ostracoden, p. 650, pi. i., figs. 29-31,
60, 61.

1868. Cypris incongruens, Brady, Mon. rec. Brit. Ostrac, p. 362, pi. xxiii., figs. 16-22.

Additional localities. — Seaton Delaval, Northumberland ; Rainton and Seaton-
Carew, Co. Durham ; Weston-on-the-Green, Oxfordshire (A. M. N.), near Staithes,
Yorkshire (G.S.B.)

Apparently generally distributed through the British Islands, but most
commonly in slightly brackish water : in such situations it often occurs abundantly
and of large growth.

L 2

74 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Distribution. — Norway (G. O. Sars) ; Sweden (Lilljeborg!); Belgium (Plateau);
France (Moniez) ; Prussia (Zaddach!); Pomerania (Willi. Midler!); Geneva (Jurine);
Hungary (Orley); Bavaria, Sicily, Russia, Madeira, and Egypt (S. Fischer);
Botanical Gardens, Palermo (A. M.N.) ; Finland (Cajander); Transylvania (Daday).

Lilljeborg is of opinion that the present species is the C. fasca of Straus-Durck-
heim. It is true that the figure more closely resembles the outline of C. inconyruens,
but the description and name fusca more closely apply to C. fuscata, Jurine, under
which species we have referred to it as a doubtful synonym.

3. Cypris pubera, 0. F. Miiller.
Synonymn : C. cuneata, Baird (junior), and C. punctitlata, Norman.

1785. Cypris pubera, 0. F. Miiller, Entomostraca, p. 56, pi. v., figs. 1-5.

1820. Monoculus ovatus, Jurine, Hist, des Monocles, p. 170, pi. xvii., figs. 5, 6 (junior).

1844. Cypris pubera, Zaddach, Syn. Crust. Prussic. Prod., p. 34.

1844. Cypris striata, Zaddacb, Syn. Crust. Pruss. Prod., p. 32 (junior).

1851. Cypris pubera, S. Fischer, Ueber das Genus Cypris, p. 154, pi. viii., figs. 1-8.

1853. Cypris pubera, Lilljeborg, De Crust, ex ord. tribus, p. 109, pi. x., figs. 1-5.

1868. Cypris punctitlata, Brady, Mon. rec. Brit. Ostrac, p. 365, pi. xxvi., figs. 1-7; pi. xxxvi., fig. 11.

1868. Cypris pubera, Heller, Unters. fiber die Crustaceen Tirols, p. 83.

Additional localities. — Town Hill Loch, Dunfermline (D. R.): Hemsworth Dam,
Yorkshire; freshwater pond on Seaton Marsh, Co. Durham (G. S. B.). The British
Museum collection contains specimens from Highgate Ponds, max*ked C. tristriata.

Distribution. — Norway (G. 0. Sars); Sweden (Lilljeborg!); Denmark (0. F.
Miiller) ; Belgium (Plateau) ; France (Moniez) ; Prussia (Zaddach !) ; Pomerania
(Wilh. Miiller, in litt.); Geneva (Jurine) ; Tyrol (Heller !) ; Hungary (Orley); Russia
(S. Fischer) ; Finland (Cajander) ; France (Moniez !) ; Italy (Saccardo) ; Transyl-
vania (Daday).

4. Cypris virens (Jurine).
Synonym : C. tristriata, Baird.

1838. Cypris gibberala, Koch, Deutschlands Crustaceen, &c, H. xxi., 20 (junior).
1844. Cypris virens, Zaddach, Syn. Crust. Pruss. Prod., p. 35.

1844. Cypris pilosa, Zaddach, Syn. Crust. Pruss. Prod., p. 36 (= var. ventricosa, B. and R.)

1851. Cypris ornata, Fischer, Ueber das Genus Cypris, p. 157, pi. ix., figs. 7-10.

1868. Cypris virens, Brady, Mon. rec. Brit. Ostrac, p. 364, pi. xxiii., figs. 23-32 ; pi. xxxvi., fig. 1.

1870. Cypris ventncosa, Brady and Robertson, Ann. Nat. Hist., ser. 4, vol. vi., p. 12, pi. iv., figs. 1-3.

1872. Cypris pubera, Fric, Die Krustenthiere Bohmens, p. 226.

1875. Cypris virens, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 124, pi. ii., figs. 27, 28.
1887. Cypris Helena, Moniez, Note sur des Ost. Clad, et Hydrachnides observes en Normandie (Bull.
Soc. d'etudes scient. de Paris), separate copy, p. 2.

of the North Atlantic and North- Western Europe.

75

Distribution. — Norway (G. 0. Sars); Sweden (Lilljeborg!) ; Belgium (Plateau) ;
Prussia (Zaddach) ; Pomerania (Willi. Miiller, in litt.) ; Geneva (Jurine) ; Bohemia
(Fric) ; Hungary (Orley !) ; France (Moniez) ; Transylvania (Daday).

Fossil. — Scotland.

One of the commonest and most ^widely distributed of British freshwater
species.

It is an inhabitant of grassy pools and ditches which dry up in the summer.
We do not remember to have ever found it in a large sheet of water.

Koch has not apparently met with the adult form, but there can be little doubt
that his C. gibberula is the young state of C. virens.

A large variety, with the row of bead-like tubercles on the anterior margin
largely developed, is var. monilifera of Brady. This was found by Mr. T. Scott
in pools near Loch Ascog, in Bute, and near Paisley ; it occurs also in gatherings
from the English Fen district, and may be looked upon as a sub-brackish variety.

A still more interesting variety is the C. ventricosa (B. and B,.), which has
recently been re-described from Normandy, as C. helena, by Prof. Moniez, to whose
kindness we are indebted for specimens. As far as we can judge also from the
examination of Zaddach's type specimens of C. pilosa, Zaddach (non Miiller),
which are not in good order, it is also the same form. Var. ventricosa is more
ventricose than the typical C. virens, shorter in proportion to the length, and
considerably higher, and more broadly rounded at the posterior extremity ; but
the connexion with the type is shown by the general characters, and especially
by the presence, a little within the anterior border, of the row of tubercles,
peculiarly characteristic of that species. In clean specimens these tubercles may
generally, though not always, be found more or less distinctly developed. An
intermediate form has been found by A. M. N. in a pond in Lumley Dene, Co.
Durham.

5. Cypris elliptica, Baird.
(Plate ix., figs. 5, G ; Plate xir., fig. 12.)

1820. (?) Cypris unifasciata, Jurine, Hist, des Monocles, p. 176, pi. xix., figs. 9, 10 (junior).

1846. Cypris elliptica, Baird, Trans. Berw. Nat. Club, n., p. 152, 1846 ; Ann. and Mag. Nat. Hist.,

xvii., p. 414, pi. ix., fig. 2 ; Nat. Hist, of Brit. Entom., p. 158, pi. xix., fig. xii.
1850. Cypris hirsuta, Fischer, Ueber das Genus Cypris, p. 159, pi. x., figs. 6-8.

Shell seen from the side, sub-ovate, inclining to sub-triangular, highest near the
middle ; height equal to more than half the length ; anterior extremity broadly and
evenly rounded, posterior narrowed and rounded; dorsal margin boldly arched,
highest in the middle, sloping with a gentle curve to the front, and more steeply

76 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

backwards; ventral margin slightly sinuated in the middle. Seen from above,
ovate twice as long as broad, widest in the middle, anterior extremity tapered and
acuminate, posterior rather broadly rounded. Surface smooth, beset with a few
fine, long hairs. Colour greenish, marked irregularly with darker blotches.
Length, 1*3 mm.

Found in a pond in Foxton Lane, Sedgefield, Co. Durham (A. M.N.); pond at
Highgate, July, 1846 (Baird!); pond at Stocksfield, Northumberland, Mr. H. B.
Watson (a. S. B.)

Distribution. — Sweden (Lilljeborg!) ; Sergiefskoje, Russia (S. Fischer).

The Foxton Lane specimens are larger than the Swedish ones of Professor
Lilljeborg, but do not differ materially in other respects. The hirsute character is
absent ; but as the specimens had been kept in the dry state and loose in a box for
twenty-five years, it is not wonderful that delicate hairs should have disappeared.
We have examined Dr. Baird's types, which are in the British Museum Collection,
and believe them to be identical with the Swedish specimens of Professor Lilljeborg.

6. Cypris reticulata, Zaddach.
(Plate viir., figs. 1, 2 ; Plate xi., figs. 5—7.)

1837. Cypris tricincta, Koch, Deutschlands Crustaceen, &c, X. 1 [junior?)..

1844. Cypris reticulata, Zaddach, Synops. Crust. Prussic. Prodr., p. 24 (junior).

1844. Cypris insignia, idem, ibidem, p. 31 (Vpartim).

1851. Cypris affinis, Fischer, Ueber das Genus Cypris, p. 32, pi. x., figs. 9-11.

1865. Cypris tessellata (in part), Brady, Monog. rec. Brit. Ostrac, p. 336, pi. xxiii., figs. 39-45.

1883. Cypris affinis, Lilljeborg, International Fisheries Exhib., London, Sweden Cat., p. 146.

Shell sub-ovate, tumid ; seen from the side, sub-renif orm ; highest in the middle ;
height equal to half the length; extremities well rounded and nearly equal;
superior margin well arched, almost gibbous in the middle ; inferior very gently
sinuated ; seen from above, the outline is regularly ovate, twice as long as broad,
the greatest width being in the middle ; anterior extremity narrower than the
posterior, and acuminated, the left valve being produced to a sharp point. End
view nearly circular, except that the ventral margin is produced into a strong keel.
Surface of valve smooth, glistening, bearing scattered appressed hairs ; colour, pale
brownish-green. Length, 10 mm.

British localities. — Johnston Loch ; Possil Marsh ; Bishop Loch ; side of Paisley
Canal ; Mill Loch, Lochmaben ; Baron Loch, Peebles (D. R.) : Hairmyres, near
East Kilbride ; and Foxton, near Sedgefield, Co. Durham (A. M. N.) : Boldon
Flats, near Sunderland ; Fenham ; and pools north of Seaton Sluice, Northumber-
land (G. S. B.).

Distribution. — Sweden (Upsala), (Lilljeborg!); Sergiefskoje, near Peterhof,
Russia (S. Fischer) ; Prussia (Zaddach !).

of the North Atlantic and North -Western Europe.

77

C. affinis comes very near to C. fusca and C. obliqua, but is more tumid than the
former, as well" as somewhat different in lateral outline. From the latter it may be
known by the valves not being obliquely placed, nor the shell punctated. More-
over, the curious inequality of the two valves, that of the left side being elongated
and overlapping in front, gives the species a special peculiarity of its own.

The "tessellated" forms referred in the "Monograph" to C. tessellata, Fischer,
are really immature examples of one or more species, chiefly of C. affinis, Fischer,
a species which, in its adult form, has only recently been recognized as British.
Tesselation seems to arise from the presence, in the substance of the shell, of
symmetrically arranged lacunas, which become, as age advances, filled up and
obliterated by deposit of calcareous matter. Rapidity of growth is probably
favourable to the production of the tesselated structure, and may account for its
occasional appearance in shells of full size, which, as a rule, possess none of it.
In C. affinis the tesselation is found in shells of almost full size ; and as the
shell remains always very thin, it is probable that growth here is unusually rapid.
C. strigata occurs in little grassy spots, which dry up again very quickly after
rain ; its great size thus necessitates rapid growth, and remains of tesselation may
be seen at times even in the adult. The character of the tesselation varies
considerably in different species ; but, in one form or another, we have observed it
in the young of C. virens, C. pubera, C. obliqua, C. affinis, C. fuscata, C. incongruens,
C. prasina, C. crassa, and E. strigata, and these are all the true C}^prides of
which we have in our collections the very young stages to examine. Erpetocypris
rep tans, though it inhabits localities similar to those of E. strigata, and is probably
of equally rapid growth, seems to form an exception to the rule, having in all its
stages a perfectly structureless shell. For varieties of tesselation, see Plate xii.

The C. insignis of Zaddach is represented in his collection by two forms,
one of which is certainly referable to the species now under consideration ; the
other probably to C. dromedaria. But his description, " superficiis marginisque
laeves," is not correct as applied to the former and tesselated form. Zaddach quotes
doubtfully as a synonym, Monoculus unifasciatus, Jurine, which species is also
recorded by M. Plateau from Belgium, but without description or figure.

7. Cypris obliqua, Brady.

(Plate xii., fig. 10.)

1868. Cypris obliqua, Brady, Mon. rec. Brit. Ostrac, p. 364, pi. xxiii., figs. 33-38.

Additional localities. — Lewis ; Isle of Skye ; Bute ; Cumbrae ; Derwentvvater
(D. R.) : Nostell Lake and Hemsworth Dam, Yorkshire ; Blackmere, Shropshire;
White Loch, Kirkcudbrightshire; High Cross Tarn, Coniston (G. S. B.) : Horsey

78 Brady and Norman — Monograph of the Marine and Freshivater Ostracoda

Mere and Whittlesea (Gr. S. B. and D. R.) : Crag Lake, Northumberland (A. M. N.)

Apart from difference of shape, the punctate shell of this species helps to
distinguish it from the two preceding species.

Distribution. — France (Moniez ! recorded by him as C. unifasciata.)

8. Oypris yibbosa, Baird.

1868. Cypris yibbosa, Brady, Mon. rec. Brit. Ostrac, p. 366.

This species is unknown to us. Dr. Baird's description may perhaps be taken
to refer either to Cypris prasina or Cyprois flava.

9. Cypris prasina, Fischer.
1850. Cypris strigata, Baird, Brit. Entom., p. 157 (non Miiller).

1855. Cypris prasina, Fischer, Beitrag zur Kenntniss der Ostracoden, p. 644, pi. xix., figs. 9-13.
1868. Cypris salina, Brady, Mon. rec. Brit. Ostrac, p. 368, pi. xxvi., figs. 8-13.

1870. Cypris fretensis, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 13, pi. iv.,
figs. 7-9.

1874. Cypris salina, Brady, Crosskey, and Kobertson, Post-tert. Entom., p. 124, pi. i., figs. 17-19.

The typical form of this species must, we think, be taken to be the banded
variety described in the "Monograph of Recent British Ostracoda." In Fischer's
description certain markings are noticed somewhat vaguely, but are not given in
the figures accompanying his memoir, and the specimen on which C. fretensis was
founded is destitute of markings altogether, but is otherwise indistinguishable
from C. salina ; the characters on which the separation was made now appear to
us insufficient to mark a distinction of species.

Additional localities. — Several East Anglian localities have yielded the unbanded
[fretensis) form — River Deben, Breydon Water, Lake Lothing, Somerton Broad,
Whittlesea Dyke (B. and R.); Dykes on Cardiff Moor (Mrs. Robertson); Isle of
Lewis (D. R.) ; Rainton, Co. Durham (A.M. N.)

Distribution. — Fischer's specimens were found near Palermo. Professor Lillje-
borg has found it in Sweden (!), and we have specimens collected by Mr. E. C.
Davison in the river Scheldt; by the Marquis de Folin, in Adour Maritime,
France ; and by Prof. Moniez at Lille ; Pomerania (Wilh. Miiller !).

Fossil. — Scotland (Crofthead).

of the North Atlantic and North-Western Europe.

79

10. Cypris (?) cambrica, Brady and Robertson.

(Plate via., figs. 12, 13.)

1872. Cypris (?) cambrica, Brady and Eobertson, Ann. Nat. Hist., ser. iv., vol. ix., p. 55, pi. ii., figs. 3, 4.

Shell seen from the side, sub -triangular ; greatest height situated behind the
middle, and equal to half the length ; anterior extremity obtusely, posterior rather
obliquely rounded ; superior margin boldly arched, slightly gibbous behind the
middle ; inferior almost straight. The outline, as seen from above, is elongated,
with equally tapering acuminate extremities ; greatest width in the middle, and
considerably less than half the length. Shell thin, semi-transparent, yellowish.
Length '75 mm.

We are unable to add anything to what was previously written respecting the
single specimen (an empty shell) on which this species was founded. The specimen
was taken off Penarth Head, South Wales, on a muddy bottom, and may very
probably have been washed down from fresh water.

11. Cypris ornata, O. F. Muller.

(Plate viii., figs. 8, 9.)

1785. Cypris ornata, Muller, Entomostraca, p. 51, pi. iii., figs. 4-6.

1820. Monoculus ornatus, Jurine, Hist. Nat. des Monocles., p. 170, pi. iii., figs. 4-6.

1838. Cypris conchacea, Koch, Deutschlands Crustaceen, &c, H. xxi., 12, 13, 14.

1844. Cypris ornata, Zaddacli, Synops. Crust. Prussic. Prodr., p. 33.

1853. Cypris ornata, Lilljeborg, De Crust, ex ord. tribus, p. 110, pi. x., figs. 19, 20 ; pi. xii., fig. 4.

Cypris ornata has been described by Muller, Jurine, and Lilljeborg, and these
three authors seem to have had in view the same species ; but Fischer appears not
to have seen the true C. ornata, and describes under that name specimens referable
to C. virens, which indeed he erroneously identifies with C. ornata.

Shell, seen from the side, oblong, sub-reniform, higher in front than behind ;
greatest height situated a little in front of the middle, and equal to half the length ;
extremities rounded, posterior much narrowed ; superior margin much elevated in
front of the middle, thence sloping with a gentle curve backwards ; inferior
sinuated in the middle. Seen from above, the outline is oblong-ovate, about twice
as long as broad, widest in the middle, extremities acuminate and nearly equal.
When placed in a favourable light under the microscope, the shell, especially
towards the two extremities, exhibits a strongly reticulated epidermic covering,

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. M

80 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

the surface smooth and sinning, bearing a few scattered hairs ; variously coloured,
but usually pale green, variously banded with dark green and orange. The setae
of the antennae are well developed. Length 2*3 mm.

This is certainly one of the finest of European Ostracoda, both as to size and
colouring. Those which come nearest in external appearance are E. reptans, and
E. strigata to which it bears not a very distant relation in size, shape, and colour.
The well-marked anterior elevation of the shell, and its greater width, are
characters sufficiently distinctive, apart from the structure of the antennae.

British localities. — The only known British specimens of this species were
taken in a pond at Shotton Hall, Co. Durham, in May, 1855 (G. S. B.)

Distribution. — Sweden (Lilljeborg !) ; Denmark (Miiller) ; Belgium (Plateau) ;
France (Moniez) ; Prussia (Zaddach!); Pomerania (Wilh. Miiller!); Switzerland
(Jurine); Hungary (Orley) ; Transylvania (Daday).

12. Cypris clavata, Baird.
(Plate ix., figs. 15, 16.)

1853. Cypris clavata, Lilljeborg, De Crust, ex ord. tribus, p. 121, pi. xi., figs. 5-7 (but not synonyms).
1868. Cypris clavata, Brady, Mon. rec. Brit. Ostrac, p. 367.

Shell somewhat wedge-shaped, highest in front of the middle ; height less than
half the length ; anterior extremity very obtuse, almost truncate, very high and
broadly rounded ; posterior much narrower, rounded, scarcely more than half the
height of the anterior ; dorsal margin gibbous in front of the middle, thence sloping
with a long and tolerably even declination to the posterior extremity ; ventral
margin slightly incurved centrally, and a little convex at the extremities. Seen
from above, lanceolate ; breadth scarcely more than one-third the length ; both
extremities narrow, the anterior the narrower. Colour (in spirits) pale green,
clouded with yellow, and two darker oblique lines behind the middle. Valves
sparingly setose. Length 2*4 mm. The setae of the antennal swimming brush
reach to the apex of the claws, as in the typical Cyprides. The species cannot there-
fore be identified with C. pardbolica (Koch), which, according to that author, is
unable to swim.

The foreign specimen of this remarkably fine Cypris, from which we have
drawn up the foregoing description, and which we have figured, is one of Lilljeborg's
types, and was taken by him, June 6, 1852, at Nobbelof, near Lund, Sweden. We
have also received examples, taken at Greifswald, in Pomerania, from Herr Wilh.
Miiller. There seems not the slightest reason to doubt that Lilljeborg was right in
assigning his specimens to the C. clavata of Baird. It closely accords with figure
and description of that species.

of the North Atlantic and North -Western Europe.

81

Dr. Baird found C. clavata "in a pond near Copenhagen Fields, July, 1886."
That spot has long been built over. C. clavata has not since been found in our
islands ; but it must be remembered that those who have been working at the fresh-
water Ostracoda have almost entirely confined their investigations to Scotland and
the North and East of England. Much yet remains to be done in the South and
West.

13. Cypris fischeri, Lilljeborg.
(Plate x., figs. 3, 4; Plate xn., fig. 2.)

1851. Cypris fasciata, Fischer, Ueber das Genus Cypris, p. 151, pi. v., gs. 9-12 ; pi. vi., figs. 1, 2 ;

and pi. xi., fig. 9 (non C. fasciata, Miiller).
1883. Cypris fischeri, Lilljeborg, International Fisheries Exhibition, London, Sweden Cat., p. 146.

Shell of female long, siliquose, highest behind the middle ; height, scarcely more
than one-third the length; anterior extremity broadly and a little obliquely rounded,
most produced below ; posterior extremity narrower than the anterior, greatest
projection below the centre, and here a slight appearance of angularity, thence
sweeping upwards and backwards to about one-third the length of the valves, where
they attain their greatest height; dorsal margin consisting of the just described
sweep behind, a central portion straight or even slightly concave, and in front of
this, at the commencement of the anterior slope, another very slight sinuation ;
ventral margin slightly concave centrally ; left valve larger than the right, which
falls short of, and closes markedly within, it at the posterior extremity. Seen from
above, three times as long as broad, with nearly parallel sides ; termination in front
acute, the sides there gradually converging ; behind narrowly rounded, the over-
lapping of the left valve is very evident by its projection. Colour (in spirit
specimens), pale green, blotched with yellow centrally. The shell is furnished with
long but scattered setae, very conspicuous on the margin. Length 2 mm.

Specimens not quite adult are of nearly equal height throughout, with the
dorsal line much straighter. It is from such a specimen that Fischer's figure
appears to have been taken.

The antennae are furnished with long plumose setae at the end of the third joint.
The abdominal rami (as correctly figured by Fischer) have the hinder side of the
distant half of the limb minutely pectinate, with very microscopic spinules, and
both claws have also very finely-pectinated edges.

The above description and the figures are made from specimens exhibited by
Professor Lilljeborg at the International Fisheries Exhibition, which were found by
him atUpsala, Sweden, June 7, 1882. The only other examples known are those
taken by Fischer in Russia.

M 2

82 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

14. Cypris triyonella, Brady.

18G8. Cypris trigonclla, Brady, Mori. rec. Brit. Ostrac, p. 3G9, pi. xxv., figs. 41-44.

The only known specimens of this species are those mentioned in the " Mono-
graph," as found by A. M. N., in a gathering made by the late Mr. George Barlee.

The French specimens recorded by Prof. Moniez under this name we find, from examples kindly
sent to us, to be the young stage of C. wrens.

15. Cypris crassa, Muller.
(Plate viii., figs. 10, 11.)

1785. Cypris crassa, Muller, Entomostraca, p. 61, pi. vi., figs. 1, 2.

1844. Cypris ovata, Zaddach, Syn. Crust. Prussic. Prodr., p. 37 (non Jurine).

1851. Cypris dromedarius, S. Fischer, Ueber das Genus Cypris, p. 153, pi. vii., figs. 5-9.

1883. Cypris dromedarius, Lilljeborg, International Fisheries Exhibition, London, Sweden Cat., p. 146.

Shell seen laterally, sub-reniform ; greatest height situated near the middle, and
equal to half the length ; anterior extremity wide, obtuse, only very slightly
rounded ; posterior much narrower, produced and moderately rounded ; the dorsal
margin is not very strongly arched, and presents two gibbous elevations, the anterior
being the more prominent of the two ; there is a rather steep incurved slope towards
the posterior extremity ; ventral margin deeply sinuated in the middle Seen from
above, ovate, more than twice as long as broad ; widest in the middle ; extremities
produced and sharply mucronate. Swimming setae of antennas well developed.
Shell-surface smooth, shining, and delicately reticulated. Length, 2*1 mm.

This species is described from specimens in Dr. Norman's collection, taken
in Sweden by Professor Lilljeborg.

Distribution. — Sweden (Lilljeborg!); Russia (Fischer).

16. Cypris bispinosa, Lucas.
1868. Cypris bispinosa, Brady, Mon. rec. Brit Ostrac, p. 366, pi. xxvi., figs. 14-17.

Additional locality. — In a pool in a small island at Valentia, Ireland (A. M. N.).

This splendid species in the three localities in which it has occurred has been
taken near the sea. It is probable, therefore, that it is an inhabitant only of
water which is slightly brackish.

of the North Atlantic and North -Western Europe.

83

ADDITIONAL SPECIES EECORDED FROM N.-W. EUROPE, UNKNOWN TO US.

Cypris rubra (J urine).

Plateau (p. 57) records this from Belgium. Jurine's description of Monoculus
ruber is very brief, as follows : "II differe de 1' orange" (i. e. Cypris incongruens) par
une couleur moins vive, par un transparence moindre dans la coquille, et surtout
par une large zone colorde qui latraverse dans le milieu. Longueur, \ de ligne."

The figure (pi. xviii., figs. 3, 4, Jurine), is very like that of C. aurantia (= incon-
gruens), the only difference appearing to be a somewhat greater sinuation of the
ventral margin. We doubt its specific distinctness.

Cypris quadripartita, Plateau.
Cypris quadripartita, Plateau, Les Crustaces d'eau douce de Belgique, p. 56, fig. 28.

M. Plateau gives the following description : — Valves seen laterally, almost
exactly elliptical ; seen from above moderately wide in the middle, and narrower
in front than behind ; seen endwise, the outline is triangular, with rounded angles,
the upper angle corresponding with the hinge-line. (The figure shows a deep
furrow in the middle of the ventral, and a shallow one on the dorsal margin.)
Valves covered with short hairs and finely punctured ; setae of the antennae and of
the first pair of feet very short. Length, 1*3 mm. Colour, pale green, mottled
with yellow, a line of dark brown along the dorsal margin, and another trans-
versely across the middle of each valve. Those lines divide the surface into four
equal parts, whence the name quadripartita.

M. Plateau found this species only once in the neighbourhood of Ghent.

Cypris strausii, Plateau.
Cypris Strausii, Plateau, Les Crustaces d'eau douce de Belgique, p. 55, fig. 26.

M. Plateau gives the following characters for this species : — Shell elongated,
enlarged at the extremities, concave in the middle of the back ; colour brown or
grey, or almost white ; valves marked with small brown patches ; surface clothed
with hairs ; antennae provided with very short setae ; ova with yellowish-brown
nuclei. Length, 1*3 mm.

84

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

This species is quite unknown to us, and was found, in the month of May, by
Professor Plateau at Sclayn (Namur) in ditches by the road between Namur and
Andenne. It may be noted that M. Plateau's figure is not unlike Limnicythere
sancti-patricii : it is, however, twice as large as the last-named species, and differs
also in other respects.

Genus V. — Erpetocypris, n. g.
(From epnerov, a creeping thing.)

General characters of the animal closely approaching those of Cypris ; but the
setae of the third joint of the lower antennas are short, not nearly reaching the
apex of the terminal claws, and are not plumose. The second pair of jaws have
branchial plates, as in Cypris. The power of swimming is lost, and the habits of
the animals, which creep along the bottom, are thus very different from those of
Cypris.

[Type. — Erpetocypris reptans (Baird).]

1. Erpetocypris reptans (Baird).

(Plate xiii., fig. 27.)

Synonym : C. virescens, Brady.

1850. Candona similis, Baird, Brit. Entom., p. 162, pi. 19, figs. 2, 2a (pullus).

1868. Cypris reptans, Mon. rec. Brit. Ostrac, p. 370, pi. xxv., figs. 10-14 ; pi. xxxvi., fig. 4.

1870. Cypris ornata, Heller, Untersuch. fiber die Crustaceen Tirols, p. 92.

1872. Cypris reptans, Fric, Die Krustentliiere Bohrnens, p. 226, fig. 24, a-b.

1872. Candona similis, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. ix., p. 52, pi. i.,
figs. 1, 2.

1875. Cypris reptans, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 128, pi. ii., figs. 81, 32.
This is a common British species.

C. ornata of Heller is, as shown by specimens kindly sent to us by Professor
Heller, not the true C. ornata, but the present species.

The caudal rami have the posterior margins fringed with minute setae
arranged in six quite separate pectinated series of about eighteen each.

Distribution. — Norway (G. O. Sars); Sweden (Lilljeborg !) ; Prussia (Willi.
Muller, in litt.); Tyrol (Heller!); Bohemia (Fric); Palermo (A. M. N.) ; Lac
d'Ossegor, Etang de la Negresse, etc., near Bayonne, S.W. France, Marquis de
Folin (G. S. B.). ; Transylvania (Daday).

Fossil. — England.

of the North Atlantic and North -Western Europe.

85

2. Erpetocypris strigata (0. F. Miiller).
(Plate viii., figs. 14, 15.)

1785. Cypris strigata, 0. F. Miiller, Entornostraca, p. 54, pi. iv., figs. 4-6.

1838. Cypris lutaria, "Koch, Deutsclilands Crustaceen, H. 21, p. 15 (variety).

1844. Cypris Jurinii, Zaddach, Synops. Crust. Pruss. Prod., p. 36.

1851. Cypris Jurinii, Fischer, Ueber das Genus Cypris, p. 152, pi. vi., figs. 3-9 ; pi. vii., figs. 1-4.

1853. Cypns Jurinii, Lilljeborg. De Crust, ex ord. tribus, p. 110, pi. x., figs. 19-22 ; pi. xii., fig. 4.

1853. Cypris lucida, id., ib., p. 122, pi. xxv., figs. 7-10 {variety),

1870. Cypris ornata, Brady (non Miiller), Nat. Hist. Trans. Nortbumb. and Durham, vol. m., p. 364,
pi. xiv., figs. 1-3.

1883. Cypris strigata, Lilljeborg, Cat. International Fisheries Exhibition, London, Sweden Cat., p. 147.

Shell elongated, not much higher in front than behind ; seen from the side,
sub-ovate, broadly rounded in front, slightly narrower behind ; superior margin
evenly and moderately arched, highest in the middle ; inferior nearly straight ;
height equal to rather more than half the length. Seen from above, oval, widest
in the middle, and tapering evenly towards the ends, which are pointed ; the
anterior rather more obtuse than the posterior; width somewhat less than the
height. End view almost circular. Surface of the shell smooth, variously banded
with pale yellow and green. Setose brush of the antennae very short, almost
rudimentary. Length, 2*5 mm.

We have here taken as the type of E. strigata Swedish specimens so named by
Professor Lilljeborg, which are now in the collection of Dr. Norman.

British localities. — Duddingston Loch, Ponds near Taymouth Castle and Port
Glasgow, Mr. T. Scott (Gr. S. B.): Thornton Hall, Lanarkshire; Isle of Cumbrae;
Burnside Loch, near Glasgow; Little Loch, near Barhead; and Hayston Dam,
Peebles (D. E.) : grassy pools at Tilmire, near York (A. M. N.) ; stream in F dwell
Cemetery, Sunderland (G. S. B.). These last-named specimens were originally
referred (loc. cit.) to C. ornata.

Distribution. — Norway (G. 0. Sars!); Sweden (Lilljeborg!); Denmark (Miiller) ;
Prussia (Zaddach !) ; Hungary (Orley) ; Russia (Fischer).

We have given C. lucida of Lilljeborg as a synonym of this species on the
authority of the author, who writes to us that he is now convinced that the form
described by him is "an example of C. strigata somewhat more than usually
excavated at the lower margins of the valves."

86 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

3. Erpetocypris fasciata (0. F. Miiller).
(Plate ix., figs. 13, 14; Plate xn., fig. 1.)

1785. Cypris fasciata, Miiller, Entomostraca, p. 53, pi. iv., figs. 1-3.
1837. Cypris ephippiata, Koch, Deutsclilands Crustaceen, H. 12, figs. 1, 2.
1844. Cypris fasciata, Zaddach, Synops. Crust. Pruss. Prod., p. 34.

1863. Cypris angustata, G. 0. Sars, Om en i Sommeren 1862 foretagen Zoologisk Reise i Christianias

og Trondhjems Stifter, p. 29.
1868. Cypris fasciata, Claus, Beit, zur Kennt. der Ostrac, Entwick. von Cypris, pi. i., figs. 9-11 ; pi. ii.,

figs. 12-21.

1870. Cypris fasciata, Heller, Untersuch. fiber die Crustaceen Tirols, p. 91.

Shell compressed, elongated ; seen from the side, sub-triangular, or siliquose ;
greatest height in the middle, and equal to somewhat more than one-third of the
length ; extremities rounded, the posterior much narrowed ; dorsal margin gently
arched, steeper behind, and slightly incurved just in front of the hinder extremity;
ventral nearly straight. Seen from above, the outline is compressed, ovate, thrice
as long as broad, widest in the middle, and tapering evenly to the extremities,
which are sharply acuminate. The surface of the shell is smooth, white, and
marked with two conspicuous transverse green bands, the anterior band generally
deeper in colour and more sharply defined than the posterior. Length, 1*55 mm.

The description is drawn from Swedish specimens in the collection of Dr.
Brady, for which he was indebted to the kindness of Professor Lilljeborg. It may
be noted that the green banding of the shell varies much in different specimens,
and that though the anterior band is usually well defined, the posterior one is
liable to become a diffuse clouding extending over a considerable portion of the
shell ; sometimes the two bands are coalescent, the shell taking on a general green
colouration, and in other cases the colouring may be almost entirely absent.

The caudal rami have the distal hinder edge smooth, and not minutely pecti-
nated, as in C. fscheri, while the claws are very strongly pectinated, instead of
minutely so, as in the case of C. fischeri.

Distribution. — Norway (Gr. 0. Sars, as C. ephippiata)) Sweden (Lilljeborg!).
Denmark (Miiller); Prussia (Zaddach!); Pomerania (Willi. Miiller!); Tyrol
(Heller !) ; Hungary (Orley) ; Bedestresser See, North Germany, S. A. Poppe !
(Q. S.B.)

of the North Atlantic and North -Western Europe.

87

4. Erpetocypris serrata (Norman).

1868. Cypris serrata, Brady, Mori. rec. Brit. Ostrac, p. 371, pi. xxv., figs. 15-19 ; pi. xxxvi., fig. 3.
1880. Cypris bicolor, Wilhelm Miiller, Zeits. fiir ges. Naturwissensch., Bd. vi., p. 236, pi. iv., figs. 24-26.
1886. Cypris zetikeri (Toth and Chyzer), Orley, Ueber die Entomostraken Fauna von Budapest, p. 7.
(Temieszetrajzi Fiizetek., vol. x.)

Additional localities. — Whittlesea; River Nene at Peterborough (G. S. B. &
D. R.).

Distribution. — Arnstadt, Thuringen (Wilh. Miiller !), Hungary (Orley !) ; France
(Moniez); Transylvania (Daday).

We are indebted to Herr Wilh. Miiller for types of his C. bicolor, and to
Professor Orley for types of the C. senkeri of Toth and Chyzer. Herr Miiller
has already himself referred C. bicolor to the present species, of which also
C. senkeri is another synonym. The spirit-preserved specimens of the latter are
of paler hue than British examples, the ground colour being light green ; the
spines of the anterior margin are not developed, as in the types, but the backward-
directed spines of the posterior margin are present as usual.

5. Erpetocypris tumefacta (Brady and Robertson).
(Plate viii., figs. 5—7 ; Plate xm., fig. 18.)

1870. Cypris tumefacta, Brady and Robertson, Ostracoda and Foraminifera of Tidal Rivers, Ann. Nat.
Hist., ser. iv., vol. vi., p. 13, pi. iv., figs. 4-6.

Shell very tumid ; seen from the side, sub-reniform, somewhat depressed in
front ; greatest height in the middle, and equal to rather more than half the
length ; extremities rounded ; superior margin boldly arched ; inferior gently
sinuated in the middle. Seen from above, broadly ovate, acutely mucronate in
front, well rounded behind ; sides sub-parallel ; greatest width situated in the
middle, and rather greater than the height. End-view sub-rhomboidal, pointed
above, broadly rounded below ; sides excessively convex. Shell perfectly smooth,
opaque white or cream-coloured, with clouded yellow patches, and sparingly
coated with very fine hairs. Three tufts of very short non-plumose antennal setae,
one consisting of four setae on the penultimate joint, another of seven or eight
setae on the antepenultimate, which also bears a fascicle of about four still smaller
setae. Length, 0*9 mm.

Seen laterally this species is not unlike C. virens or C. incongruens, but seen from
above or endwise the difference of contour is very marked, being very gibbous.

British localities. — The types were found in Northumberland, but it has since
been taken in the river Lathkill, Derbyshire, and near Sunderland (Gr. S. B.), and
in the following Scotch localities by D. R. : Cum brae ; Peebles ; Lochmaben ;

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. N

88 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Lochgoin ; Yetholrn ; Eaglesham ; and Bishop and Woodend Lochs : near Glasgow ;
also near Taymouth Castle ; near Paisley ; in pools near Greenan Loch. In
pools by Loch Ascog and Loch Fadd ; and at Tarbert, Loch Fyne (Mr. T. Scott).

Distribution. — Common in the neighbourhood of Christiania, Norway (G. 0.
Sars in litt.).

6. Erpetocypris robertsoni, n. sp.

Shell seen from the side, sub-reniform, highest just behind the middle ; height
equal to half the length; anterior extremity evenly rounded, posterior broader
and obliquely rounded ; dorsal margin boldly arched, rather depressed in front,
the greatest height being behind the middle, forming
a bold and steep curve backwards ; ventral margin
gently sinuated, and showing a slight protuberance
near the middle ; seen from above, regularly ovate,
widest in the middle, and nearly thrice as long as
broad, compressed and acuminate in front, rounded
off behind. Surface of the valves smooth, greenish,
mottled with markings of deeper green and brown.
Length 1*6 mm.

Habitat. — Hayston Dam, Peebles ; and Portree, Isle of Skye [Mr. D. Robertson).

It is very difficult to indicate a distinct line of separation between this species
and E. strigata on one hand, and E. olivacea on the other. The difference in form
of shell will be best appreciated if put in tabular form as follows : —

■S l

Erpctocypris robertsoni.

Lateral View.
strigata, highest in front, .

olivacea, highest in middle,

robertsoni, highest behind the middle,

Dorsal View.

extremities nearly equal, moderately

compressed, acuminate,
extremities equal, very slightly

tapered, broad, sub-acuminate,
tapered and acuminate in front,

rounded behind.

The caudal rami in E. strigata have the apical claws long and slender, and
between them and the marginal seta there is a considerable interval ; in E. robert-
soni the two principal claws are short and stout and not much curved, while the
marginal seta is very small and slender, and is closely approximated to the rest ;
in E. olivacea the apical claws are, as in E. robertsoni, short and stout, the marginal
seta being also very thick, and separated by a short interval from the others.

E. robertsoni has been found only in two localities : Hayston Dam, near Peebles,
and in the river at Portree, Isle of Skye. In both places it was taken by our
friend Mr. David Robertson, after whom we have much satisfaction in naming it.

of the North Atlantic and North -Western Europe.

89

7. Erpetocypris olivacea, nov. sp.
(Plate L, figs. 3, 4.)

Shell seen from the side, elongated, subreniform, greatest height in the middle,
and equal to half the length ; anterior extremity evenly, posterior obliquely
rounded, dorsal margin forming a flattened arch, and sloping more steeply behind
than in front ; ventral gently sinuated ; seen from above, ovate ; more than twice as
long as broad, widest in the middle, extremities obtusely pointed and nearly equal ;
shell smooth and shining, transparent, mottled, deep olive green. Length, 1*4 mm.

This pretty species was found abundantly amongst weeds in the River Lath-
kill, Derbyshire, in August, 1885 (G. S. B.). Duddingston Loch, near Edinburgh,
1887, Mr. T. Scott!

Genus VI. — Cypridopsis, Brady.

[Type, C. vidua (Miiller).J

1. Cypridopsis vidua (Miiller).
Synonym : C. sella, Baird.

1837. Cypris muculata, Koch, Deutschlands Crustaceen, &c, H. 10, 2.
184(4 ?). Cypris striyata, idem, ibidem, H. 36, 19.

1868. Cypridopsis vidua, Brady, Mon. rec. Brit. Ostrac, p. 375, pi. xxiv., figs. 27-36, 46.

1868. Cypris vidua, Claus, Beitriige zur Kenntniss der Ostracoden, Entwickelungsgeschichte von

Cypris, pi. i., figs. 6-8.

1869. Cypridojms obesa, Brady and Bobertson, Ann. Nat. Hist. ser. iv., vol. iii., p. 364, pi. xviii.,

figs. 5-7.

1870. Cypridopsis obesa, idem, ibidem, ser. iv., vol. vi., p. 15.

1870. Cypris vidua, Heller, Unters. fiber die Crustaceen Tirols. p. 90.
1872. Cypris vidua, Fric, Die Krustenthiere Bobmens, p. 227.

1874. Cyjmdopsis obesa, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 128, pi. i., figs. 1-4.

The banded typical form of C. vidua is widely distributed in fresh water.
The form for which the specific name obesa was proposed differs in being devoid
of coloured bands, and usually of rather coarser appearance. It occurs commonly
in brackish or sub-brackish water, though by no means confined to situations of
that kind.

Distribution. — Norway (Gr. 0. Sars); Sweden (Lilljeborg!) ; Denmark (0. F.
Miiller) ; Prussia (Zaddach !) ; Switzerland (Jurine) ; Thuringen (Willi. Miiller, in
litt.) ; Tyrol (Heller) ; Bohemia (Fric) ; Hungary (Orley) ; Russia (Fischer) ;
Botanical Gardens, Palermo (A. M. N.); North Germany (Poppe !) ; Normandy
(Moniez) ; Transylvania (Daday).

Fossil. — England .

N2

90 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

2. Cypridopsis aculeata (Lilljeborg).

1868. Cypridopsis aculeata, Brady, Mori. rec. Brit. Ostrac, p. 376, pi. xxiv., figs. 16-20; pi. xxxvi.,
fig. 10.

1838. Cypris villosa, Koch, Deutschlands Crustaceen, &c, H. 21, 24.

Additional localities. — Scilly Islands, many of the broads of Norfolk and Suffolk,
and dyke at Whittlesea (G. S. B. & D. R.): River Thames; very abundant at
Monkton Paper Mills Co. Durham (G. S. B.) : Cardiff Moor (Mrs. Robertson) :
Seaton Delaval, Northumberland; Belfast; Newport, Co. Mayo (A. M. N.): Tarbert,
Argyleshire, Mr. T. Scott (G. S. B.) : Isle of Skye (D. R.).

Distribution. — Sweden (Lilljeborg !); River Scheldt, Holland, Mr. E. C. Davison
(G. S. B.); Finland (Cajander); Transylvania (Daday).

3. Cypridopsis villosa (Jurine).

Synonyms: Cypris westwoodii and (?) elonyata, Baird.

1868. Cypridopsis villosa, Brady, Mon. rec. Brit. Ostrac., p. 377, pi. xxiv., figs. 11-15 ; pi. xxxvi., fig. 9.

Additional localities. — Lakes of Mayo and Gal way (G. S. B. & D. R.): New-
biggin, Northumberland (A. M. N.) : pond near Taymouth Castle, and in pools
near Lochs Fadd and Ascog, T. Scott (G. S. B.): Baslow, Derbyshire; Welbourn,
Lincolnshire; Loch Fergus, Kirkcudbrightshire (G. S. B.): Isles of Skye and
Lewis (D. R.).

Distribution. — Sweden (Lilljeborg!) ; Belgium (Plateau) ; Switzerland (Jurine) ;
Germany (Koch) ; France (Moniez).

4. Cypridopsis (?) newtoni, Brady and Robertson.
(Plate viii., figs. 16, 17.)

1870. Cypridopsis (?) newtoni, Brady and Robertson, Ann. Nat. Hist., ser. nr., vol. vi., p. 14, pi. vii.,
figs. 14-16.

1874. Cypridopsis (?) newtoni, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 129, pi. ii.,
figs. 20, 21.

Carapace, as seen from the side, reniform ; greatest height in the middle, and
equal to a little more than half the length ; extremities rounded, the anterior
being the broader of the two ; superior margin boldly and evenly arched ; inferior
sinuated in the middle. Seen from above, compressed, ovate, acuminate in front,
rounded behind ; greatest width situated near the middle, much less than the height.
Surface of the shell punctate, and covered with numerous appressed hairs. Colour,
dull green. Length, *85 mm.

of the North Atlantic and North -Western Europe.

91

Our examples of this species are not numerous, and we have not been successful
in finding perfect specimens of the contained animal. The postabdominal rami
are rudimentary, as in Cypridopsis ; but the lower antennae seem to be destitute of
the setose brush, which in that genus is usually very long. The species would
therefore appear to be an aberrant one ; but without a thorough acquaintance with
its internal structure, we think it best for the present to place it in the genus to
which it is here assigned. It approaches closely in external appearance to Cypri-
dopsis villosa and Potamocypris fulva, but is larger than either, more tumid, less
strongly arcuate, and coarser in texture than the former ; while the almost equal
and well-rounded valves, coarsely hispid surface, and ovate form when seen from
above, sufficiently distinguish it from the latter.

Habitat. — Hayston Dam, Peebles; Little Loch and Pilmuir Dam, Renfrew-
shire ; Isles of Cumbrae and Bute (D. R.) : Rivers Nene and Cam ; and dykes on
the site of Whittlesea Mere (G. S. B. & D. R.) : Loch Ruter, Kirkcudbrightshire
(A. M. N.).

Fossil. — England (Whittlesea).

5. Cypridopsis variegata, no v. sp.
(Plate viii., figs. 20, 21.)

Shell seen from the side, sub-reniform, greatest height situated just in front of
the middle, and equal to two-thirds of the length ; anterior extremity broad, well-
rounded ; posterior narrower, obliquely truncated ; dorsal margin boldly arched,
almost gibbous ; ventral sinuated in the middle ; seen from above, ovate,
fully twice as long as broad, extremities sub-acuminate. The right valve
is larger and more rounded in outline than the left, which it overlaps (though not
so broadly as in Potamocypris fulvd) on the dorsal, ventral, and posterior margins.
The shell is marked throughout with closely-set, small, rounded impressions, and
in the Lough Neagh specimens is ornamented with black bands, the ground colour
being yellowish. Length, *55 mm.

This species occurred sparingly in several gatherings made years ago, in the
English Fen District, by Messrs. Brady and Robertson ; but on account of its close
resemblance to Potamocypris fulva and Cypridopsis neivtoni it remained undescribed.
Specimens recently obtained by Mr. Robertson in the Isle of Skye, and by Dr.
Norman from a pool by the side of Lough Neagh, Ireland, by their very
characteristic colouring, seem to leave no doubt as to its specific distinctness.
The Fen district localities are the following : River Cam, at Ely ; River Nene, at
Peterborough ; and dykes near Whittlesea.

02

Brady and Norman

— Monograph of the Marine and Freshwater Ostracoda

6. Cypridopsis pic ta (Straus).

(Plate x., figs. 30, 31.)

1821. Cypris picta, Straus-Durckheim, Mem. sur les Cypris (Mem. du Museum, vol. vii.), p. 59, pi. i.,
figs. 17-19.

1867. Cypris picta, Plateau, Kecherches sur les Crust, d'eau douce de Belgique, p. 50.

Shell sub-ovate, tumid ; greatest height central, about equal to half the length ;
anterior extremity narrower than the posterior, well rounded ; posterior extremity
broadly and evenly rounded ; dorsal margin well arched throughout ; anterior
declination steeper than the posterior ; ventral margin sinuated in the middle.
Seen from above, ovate ; greatest breadth rather behind the middle, equal to the
height, or half the length ; the meeting of the valves in front is at an acute angle,
but the hinder extremity is broadly rounded. Valves finely punctate, with a few
scattered hairs. Spirit-preserved specimens are dark-green, with a white transverse
band near the front. In such specimens, however, the animal is shrunk up
towards the front part of the shell, which perhaps accounts for the apparent
absence of two bands behind. Straus says: " Couleur verte, avec trois bandes,
grises de terminant en joint en dessous." Length, *4 mm.

We are indebted to Professor G. O. Sars for specimens of this species taken at
Christiania, Norway. It has not been found in Britain.

The other recorded localities are: France (Straus-Durckheim); Belgium
( Plateau).

C. picta may be distinguished from C. vidua, its nearest ally, by its smaller
size, lesser obesity — though it is more tumid than the other species of the genus —
by the anterior extremity being less high in proportion to the posterior when viewed
laterally, and narrower in proportion to the posterior when looked at from above.

Genus VII. — Potamocypris, Brady (1870).

[Type, P. fidva, Brady. J

Shell compressed ; seen from the side, similar to that of Cypridopsis ;
valves unequal, the right much the larger, and overlapping on the dorsal and
middle of the ventral margin ; dorsal margin of the left valve somewhat flattened,
that of the right boldly arched ; hingement simple. Antennules seven-jointed,
bearing a terminal brush of long, slender setae. Antennas geniculated, four-jointed,
third and fourth joints bearing numerous setae, which however are short, not

of the North Atlantic and North-Western Europe.

93

reaching beyond the middle of the terminal claws ; last joint with two strong
curved terminal claws, and two or three short, slender seta?. Mandible stout ; palp
three -jointed, and bearing a single branchial seta near the base. There is no
verticillate duct (" glandula mucosa"), and the copulative organ is comparatively
small and simple in structure. Feet as in Cypris. Caudal rami rudimentary,
consisting only of a single slender seta.

Potamocypris fulva, Brady.
(Plate xxil, figs. 13-17.)

1868. Bairdia fulva, Brady, Mon. rec. Brit. Ostrac, p. 474, pi. xxviii., fig. 21.

1869. Bairdia fulva, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 366, pi. xviii.,

figs. 1-4.

1870. Potamocypris fulva, Brady, Nat. Hist. Trans. Northum. and Durham, p. 366, pi. xiv., fig. 4.
1874. Potamocypris fulva, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 130, pi. i., figs. 20-24.

Originally described from a specimen found in Scarpa Bay, Orkney; and a
single valve in shell-sand from Eoundstone. It has since that time been found in
the following localities : Montrose Basin ; Port Glasgow ; Karnes' Bay, Cumbrae ;
Birturbuy Bay; Biver Liffey, at Dublin (G. S. B. & D. R.) : at Fulwell Cemetery,
Sunderland ; near the mouths of several rivers in Northumberland — Warn Burn,
rivers Coquet, Wansbeck, and Blyth ; in the canal at Ackworth, Yorkshire
(G. S. B.) : in dredgings from Rothesay Bay and Cumbrae : off Penarth Head,
near Cardiff ; in the Isle of Skye, and at Rowan Bridge, Lewis ; and in dykes on
Cardiff Moor (D. R.). In a pond near Taymouth Castle; in pools near Loch Fadd
and Loch Ascog; and at Tarbert, Loch Fyne, Mr. T. Scott (G. S. B.).

It is most likely that the dredged specimens — all empty shells — were washed
down out of fresh or brackish water. The only perfect animals (with soft parts
intact) were from Fulwell Cemetery and Loch Ascog. In these cases the colour
of the shell was green, so that the colourless or dirty yellow valves, as they
usually occur, have probably undergone a post mortem bleaching.

The shell of this species has already been so abundantly figured that it is
unnecessary to give further drawings.

94

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Genus VIII. — Aglaia, Brady.

[Type, Aglaia pulchella, Brady.]

Aylaia, Brady, Les Fonds de la Mer, tome premier, p. 90.

Shell smooth, and polished, of nearly equal height before and behind, com-
pressed, sub-cylindrical. Antennules seven- jointed, beset with short setae.
Antenna; robust, and bearing at the extremities of the joints several strong curved
setae, furnished also with a small hyaline vesicle, and on the penultimate joint with
a lash of very short setae. Mandibles slender, divided at the extremity into about
five blunt teeth, and furnished with a long and narrow branchial palp. First pair
of jaws divided into four digitate segments, and having a distinct branchial
appendage ; second pair also provided with a branchial lamina and simple conical
three-setiferous palp. First pair of feet long, five-jointed, with a very long terminal
claw; second pair different from the first, flexuous, four-jointed, last joint armed
with three setae, of which one is very long and finely pectinated on the inner
margin. Post-abdominal rami moderately robust, bearing two curved terminal
claws, one seta on the anterior and two on the posterior margin. Testes disposed
round the body of the animal; verticillate duct elongated, and bearing seven
whorls of filaments.

Aglaia complanata, Brady and Robertson.
(Plate xiv., figs. 28, 29.)

1869. Aylaia complanata, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 66,
pi. xx., figs. 4, 5.

Carapace, as seen from the side, oblong, sub-reniform, highest about the middle ;
greatest height equal to less than half the length ; extremities rounded ; superior
margin evenly but slightly arched ; inferior almost straight. Seen from above,
compressed, ovate, extremities pointed ; greatest width in the middle, and not
much exceeding one-fourth of the length. Surface of the valves smooth, bearing
a few short, scattered hairs ; shell thin and fragile ; lucid spots arranged in an
irregular rosette. Length, -65 mm.

Dredged in Westport Bay, in a depth of four fathoms ; also in Roundstone Bay
(G. S. B. & D. R.): Birturbuy Bay, Ireland (A. M. N.). The generic description,
so far as the soft parts are concerned, is founded upon an examination of a
Mediterranean species (A. pulchella). We have had no opportunity of seeing the
internal parts of A. complanata.

of the North Atlantic and North -Western Europe.

95

Genus IX. — Pakacypris, G. 0. Sars.
[Type, Paracypris polita, G. 0. Sars.]
Paracypris polita, G. O. Sars.

1868. Paracypris polita, Brady, Mon. rec. Brit. Ostrac, p. 378, pi. xxvii., figs. 1-4 ; pi. xxxviii., fig. 2.

1874. Paracypris polita, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 131, pi. xv., figs. 9, 10.

1878. Paracypris polita , Brady, Mon. Ostrac. Antwerp Crag, p. 381, pi. lxiii., fig. 5.

1880. Paracypris polita, Seguenza, Le formazioni terziarie nella provincia di Reggio (Calabria), p. 861.

1880. Paracypns polita, Brady, Report Ostrac. " Challenger " Exped., p. 32.

1883. Paracypris jwlita, Seguenza, II Quaternero di Rizzolo II. Gli Ostracodi, p. 3.

1885. Paracypris polita, Carus, Prod. Faunaa Mediterranea3, p. 314.

Additional localities. — The Scilly Islands ; Roundstone Bay and Mulroy Lough,
Ireland (G. S. B. and D. R.): The Minch ; Balniacarra, Sound of Skye; off Tarbert,
Loch Fyne, 25 fathoms; Killary Bay (A. M. N.).

Distribution. — Langesund and Flekkefiord, in West Norway, 4-10 fath. (G. O.
Sars) ; off Sartoro, Bergen Fiord, 15-40 fath. ; Hardanger Fiord, off Lervig,
20-100 fath. ; Fosse de Cap Breton, Bay of Biscay, 180-200 fath. ; off Capri, Bay
of Naples, 40 fath. (A. M. N.) ; Vigo Bay, Spain (G. S. B.) ; Messina (Seguenza) ;
Wellington Harbour, New Zealand, 420 fath., " Challenger" (?) (G. S. B.).

Fossil. — Scotland ; Norway ; Calabria ; Sicily.

Genus X. — Notodeomas, Lilljeborg.

[Type, N. monacha (Muller).]

The characters which distinguish this genus from the following — Cyprois — are
as follows : — The shell is usually ribbed or keeled on the ventral surface. The
antennas are not pediform ; antepenultimate joint with the usual sensory organ and
a brush of very long swimming setae, which stretch beyond the extremities of those
springing from the last joint; penultimate and terminal joints cylindrical and
very slender, the latter as long or longer than the preceding, terminating in three
slender setae without claws or spines (vide Brady, Monogr., PI. xxxvii., fig. 3 b).
Branchial filaments of the mandible not attached to a lamina of their own, but
directly to the palp and directed downwards. The second pair of maxillae without
branchial appendages ; in the male the palps very strongly developed and
different on the two sides. Feet of the first pair small and terminating in three
setae, the middle one claw-like, and about twice as long as the other two. Caudal
rami with three claws at or near the extremity.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART U.

O

96

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Notodromas monacha (Miiller).

1844. Cypris monacha, Zaddach, Syn. Crust. Pruss. Prod., p. 31.

1837. Cypris variabilis (very young), Koch, Deutschlands Crustaceen, &c, H. 10, 3.

1837. Cypris leucomela (young), idem, ibidem, H. 10, 4.

1837. Cypris monacha (adult male), idem, ibidem, H. 11, 1.

1837. Cypris bimuricata (adult female), idem, ibidem, H. 11, 2.

1837. Cypris nubilosa (half- grown) , idem, ibidem, H. 12, 4.

1851. Cypris monacha, Fischer, Ueber das Genus Cypris, p. 146.

1854. Cyprois monacha, Zenker, Monog. der Ostracoden (Archiv fur Naturgesch. ), p. 80, pi. iii. C,
1868. Notodromas monachus, Brady, Mon. rec. Brit. Ostrac, p. 379, pi. xxiii., figs. 1-9 ; pi. xxxvii., fig. 3.
1870. Notodromas monachus, Heller, Unters. iiber die Crustaceen Tirols, p. 78.
1872. Cypris monacha, Fric, Die Krustenthiere Bohmens, p. 228.

1885. Notodromas monachus, Nordquist, Beitrag zur Kenntniss der inneren mannliehen Geschlechts-
organe der Cypriden, pis. i., ii., and iv.

Additional localities. — Gumley, Leicestershire ; Newport, Co. Mayo (A. M. N.) :
Lochrnaben ; Somerton Broad, Norfolk, and Coolbareen Lough, Co. Mayo (G. S. B.
and D. R.) : in pools by Loch Fadd, Co. Bute (Mr. T. Scott, G. S. B.).

Distribution. — Norway (G. 0. Sars); Sweden (Lilljeborg !) ; Denmark (Miiller);
Belgium (Plateau) ; Germany (Zenker, &c.) ; Bohemia (Fric); Switzerland (Jurine);
Tyrol (Heller); Hungary (Orley) ; Russia (Fischer); Finland (Cajander);
Normandy (Moniez); Transylvania (Daday).

Genus XL — Cyprois, Zenker.
[Type, C. flava (Zaddach.)]

Shell compressed ventrally, and destitute of ribs or keel. Antennae stout, the
last joint short and very narrow, bearing at the apex a twisted unguiform spine,
the distal half of which is pectinated with two series of marginal setae ; also four
simple setae almost half as long as the spine, and two much smaller ones ; the
penultimate joint bears three long, slender setae, one of which is pectinated, and
in front of these a much stronger twisted and pectinated spine like that of the
apical joint, but larger; antepenultimate joint furnished with the usual sensory
organ, and at its extremity with a group of long swimming setae. Second pair of
maxillae provided with a rudimentary branchial appendage of six plumose setae.*
Caudal rami bearing four or five claws at or near the extremity.

* This is not shown in Professor Orley's figures of the organs in C. madaraszi ; indeed he states
in the text of his memoir that it is -wanting. This, however, is an oversight : it is clearly
shown in our preparations, and closely resembles the same organ in C. dispar.

of the North Atlantic and North - Western Europe.

97

The male is smaller than the female (in C. flava), and more evenly rounded at
the posterior extremity. The palp of the second maxillse is prehensile and different
on the two sides. Reproductive organs as in Notodromas.

A grand sjDecies, by far the largest of European Podocopa, has been described
from Hungary by Professor Orley, under the name Notodromas madaraszi (TermeV
zetrajzi Fiijetek, vol. x., 1886, p. 11, Pis. x. xi.). It is not a true Notodromas,
and will fall into the present genus as Cyprois madaraszi.

The name Cyprois was proposed by Zenker as a sub-generic term to include
two species, C. (Notodromas) monacha and C. flava. The two forms agree in the
structure of the male reproductive apparatus, but the characters both of the shell
and of the contained animal seem to require that they should be placed in different
genera. In Notodromas the form of the shell in the two sexes is widely different,
and quite distinct from that of Cypris, whereas in C. flava the shell presents no
great sexual differences of form. We have, moreover, been favoured by Professor
Gr. O. Sars with specimens of the two sexes of C. (Cyprois) dentato-maryinata,
Baird, raised from Australian mud ; and in these the male organs are exactly
similar to those of Cyprois. It is remarkable that in both cases ( C. flava and C.
dentato-maryinata) the caudal rami are abnormal in having four rather long mar-
ginal setae attached near the extremity, thus differing from Cypris, which has
two long terminal and one shorter lateral seta.

Cyprois flava (Zaddach).
(Plate viii., figs. 18, 19 ; Plate xn.} figs. 13-21, 38.)

1838. (?) Cypris gibbosa, Baird, Mag. Zool. and Bot., vol. n., p. 137, pi. v., fig. 15; Nat. Hist. Brit.

Entom. (1850), p. 156, pi. xix., fig. 8.
1844. Cypris flava, Zaddach, Syn. Crust. Pruss. Prodr., p. 33.

1851. Cypris dispar, Fischer, Ueber das Genus Cypris, p. 142, pi. i., figs. 1-12 ; pi. ii., figs. 1-6.

1854. Cyprois dispar, Zenker, Monographie der Ostracoden (Archiv fur Naturgesch.), p. 81.

1883. Cyprois dispar, Lilljeborg, International Fisheries Exhibition, London, Sweden Cat., p. 147.

Shell of the female seen from the side, sub-triangular or sub-renif orm ; greatest
height situated in the middle and equal to two-thirds of the length; anterior
extremity broadly and evenly rounded; posterior oblique, steeply sloping, and
rounded off at the inferior angle; dorsal margin boldly arched; inferior slightly
sinuated in the middle. Seen from above, the outline is sub-ovate, more than
twice as long as broad, widest in the middle, much compressed in front, anterior
extremity slender, and sharply-pointed ; posterior narrow and rounded off, scarcely
pointed. Surface smooth and polished, marked with minute polygonal areolae,

0 2

98 Bridy and Norman — Monograph of the Marine and Freshwater Ostracoda

and bearing a very few fine appressed hairs. The hinder half of the valves in
the male is occupied by a series of four concentric U-shaped, opaque streaks, with
intermediate lines of perfectly pellucid shell, the whole enclosing a peninsula of
unmarked shell : these markings coincide with the convolutions of the spermatic
tubes (testes) which are apparent through the shell ; and curvilinear markings
corresponding with the ovarian tubes — entirely oj)aque and comparatively indis-
tinct— may usually be observed in the same region of the female shell. Length of
the male, 1*30 mm. ; of the female, 1*75 mm.

Habitat. — Duddingston Loch, near Edinburgh (A. M. N.).

Distribution. — Norway (G. O. Sars); Sweden (Lilljeborg !) ; Russia (Fischer) ;
Hungary (Orley) ; Prussia (Zaddach !).

Genus XII. — Candona, Baird.
[Type, C. Candida (Miiller).]

1. Candona Candida (Miiller).
(Plate x., figs. 1, 2, and 14-23.)
Synonym : Candona lucens, Baird.

1837. Cypris pellucida (?), Koch, Deutsclilands Crustaceen, &c, H. 11, 5.
1868. Cytheridea zetlandica, Brady, Mon. rec. Brit. Ostrac, p. 428, pi. xxviii., figs. 42-46.
1868. Candona Candida, Brady, Mon. rec. Brit. Ostrac, p. 383, pi. xxv., figs. 1-9, pi. xxxvi.,fig. 13, and
pi. xxxvii., fig. 1.

1870. Candona Candida, var. tumida, Brady and Bobertson, Ann. Nat. Hist., Ser. 4, vol. vi., p. 16,
pi. ix., figs. 13-15.

1870. Candona Candida, Heller, Untersucb. iiber die Crustaceen Tirols, p. 94.
1872. Cypris Candida, Fric, Die Krustentbiere Bohmens, p. 227.

1874. Candona Candida, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 135, pi. ii., figs. 29, 30.
1885. Cypris Candida, Nordquist, Beitrag zur Kenntniss der inneren mannlicben Gescblecbtsorgane
der Cypriden, p. 25, fig. 27.

Common everywhere throughout the British Isles.

Distribution. — Norway (G. 0. Sars); Sweden (Lilljeborg!); Denmark (Miiller);
River Scheldt, Holland (G. S. B.); Belgium (Plateau); Germany (Zenker, Zad-
dach, &c.) ; Switzerland ( Jurine) ; Tyrol (Heller) ; Bohemia (Fric) ; Hungary
(Orley) ; Russia (Fischer) ; Lac d' Ossegor, Cap Breton, S.W. France, Marquis de
Folin (G. S. B.) ; Normandy (Moniez !); Transylvania (Daday).

of the North Atlantic and North -Western Europe.

99

The typical form of this species we take to be that figured as such in the
" Monograph of recent British Ostracoda," but variations from the type are very
numerous, and two of these seem to require recognition as named varieties —
C. tumida and C. claviformis.

The variety tiimida (Plate x., figs. 14—17) is much shorter and stouter than the
typical form, the greatest height in the female equalling nearly two-thirds of the
length : the width more than half the length ; the outline, as seen from above, almost
elliptical. The male is much higher, and also more tumid than in the ordinary
form of the species. Lucid spots arranged in a rosette, five in number, each broadly
cuneiform, with its apex directed towards the centre of the group. Intermediate
forms are not unfrequently met with, but the tumid variety may usually be distin-
guished by the rosette -like disposition of the muscle-spots.

The male of the variety claviformis (PI. x., figs. 1, 2) is, seen laterally, very
narrow, with an almost straight dorsal line, sloping gently towards the highest
part of the shell, which is situated very near the posterior extremity, thence fall-
ing steeply backwards ; ventral margin very deeply sinuated in the middle ; height
equal to about half the length. The shell of the female is a little higher in front,
the ventral sinuation shallower, and the posterior margin oblique, and not so
broadly rounded. A form very closely approaching C. neglecta, Sars,* is represented
in Plate x., figs. 18—21. Figs. 18, 19 are from shells (female) taken in a canal at
Ackworth, Yorkshire. Figs. 20, 21 are from male shells found in a pond at
Sunderland. Figs. 22, 23 is a female shell of the ordinary type, but with con-
spicuous reticulation near the extremities, also from Sunderland.

The ordinary form of C. Candida occurs commonly in ponds and ditches ; the
variety tumida is most common in rivers and dykes subject to tidal influence, as
in the Fen district of Norfolk and Suffolk, in the rivers Nene and Cam, and in the
Warn Burn, Northumberland (Gr. S. B. and D. R.). The variety claviformis was
found in a pond at Sedgefield, county Durham (A. M. N.).

At the time of the publication of the "Monograph," the variety tumida was
unknown, and the Ostracod named Cytheridea zetlandica, having been found in
the sea, was taken to belong to the genus to which it was assigned. But as it
exactly corresponds with the variety tumida, we conclude that it must have been
washed into the sea, and it is now expunged from our list.

* Nye Bidrag til Kundskaben om Middelhavets Invertebratfauna, iv. Ostracoda Mediterranea.
(Arcbiv for Mathem. og Naturvidenskab, 1887, p. 107, pi. xv., figs. 5-7; pi. xix.)

100 Beady and Norman — Monograph of the Marine and Freshwater Ostracoda

2. Candona elongata, nov. sp.
(Plate x., figs. 24-27.)

Shell of the male (?) elongated, reniform ; seen laterally, more than twice as
long as high ; greatest height behind the middle ; anterior extremity evenly
rounded, posterior narrower and sub-angular ; dorsal margin almost horizontal for
about one-third of its length at and somewhat behind the middle, thence sloping
with an almost imperceptible curve, steeply behind but more gently towards the
front ; ventral margin very deeply sinuated in the middle. Seen from above,
elongated, sub-ovate, more than twice as long as broad, widest in the middle ;
extremities pointed ; surface smooth and polished ; yellowish white. Length,
1*4 mm. Female unknown. A form which we take to be the young male (figs.
24, 25) is rather smaller, with a less strongly arched dorsal margin, and the
ventral margin upturned and sinuated behind.

Lough Neagh, Ireland (A. M. N.).

3. Candona lactea, Baird.

1868. Candona lactea, Brady, Mon. rec. Brit. Ostrac, p. 382, pi. xxiv., figs. 55-58.
18G8. Candona detecta, Brady (variety), Mon. rec. Brit. Ostrac, p. 384, pi. xxiv., figs. 35-38 ; pi. xxxvii.,
fig. 2.

1874. Candona lactea, Brady, Crosskey, and Bobertson, Post-tert. Entorn., p. 134, pi. i., figs. 14-16.
1874. Candona detecta, Brady, Crosskey, and Bobertson (variety), Post-tert. Entom., p. 134, pi. i.,
figs. 7-9.

C. lactea approaches closely the young of C. Candida, with which it has, no
doubt, been generally confounded on the Continent. The young of C. Candida
may, however, be distinguished by being obliquely rounded behind, most pro-
duced below the middle, whereas in C. lactea both extremities are evenly
rounded. It is common in Britain.

Distribution. — Rivers Scheldt and Maas, Holland (G. S. B.) ; Lac d'Ossegor,
Cap Breton, S. W. France ; Marquis de Folin (Gr. S. B.).

Fossil. — Scotland; England; South Wales; Ireland.

of the North Atlantic and North -Western Europe.

101

4. Candona pubescens (Koch).
(Plate xii., figs. 32-37.)

Synonym : Cypris setiyera, Jones.

1837. Cypris pubescens, Koch, Deutsclilands Crustaceen, &c, H. 11, p. 5.

1838. (?) Cypris compressa, idem, ibidem, H. 21, p. 17.

1868. Candona compressa, Brady, Mon. rec. Brit. Ostrac, p. 382, pi. xxvi., figs. 22-27.
1868. Candona albicans, idem, ibidem, p. 381, pi. xxv., figs. 20-25 ; pi. xxxvi., fig. 12 (junior).
1874. Candona albicans, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 133, pi. L, figs. 10-18
(junior).

Additional localities. — Not uncommon in the Scottish Lowland lakes ; generally
distributed through the East Anglian Fen district (G. S. B. and D. R.) : Ellesmere
Canal, Blackinere, Colmere, and Osmere, Shropshire (G. S. B.) ; Duddingston Loch,
Edinburgh ; pond in Lumley Dene, Seaton Carew Marshes, and Sedgefield, all in
the county of Durham ; Tilmire, near York (A. M. N.): Lindores Loch, Fife (Mr.
T. Scott).

Distribution. — Norway (Gr. O. Sars) ; Sweden (Lilljeborg !) ; Germany (Koch) ;
Russia (Fischer); Lac d'Ossegor, Cap Breton, S. W. France; Marquis de Folin
(G. S. B.) ; Normandy (Moniez) ; Transylvania (Daday).

Fossil. — England.

The form hitherto known to us as C. albicans probably includes the young of
more than one species, all characterized by a very close and distinct punctation of
the shell. By far the greater number of these are doubtless referable to
C. pubescens, this being the form figured in the "Monograph of recent British
Ostracoda;" but the young of C. rostrata scarcely differs, except in being much
more compressed and acuminated in front.

5. Candona rostrata, nov. sp.

(Plate ix., figs. 11, 12, \2a and b ; Plate xii., figs. 22-31.)

1851. Cypris compressa, Fisclier, Ueber das Genus Cypris, p. 144, pi. ii., figs. 7-12 ; pi. iii., figs. 1-5.

Shell seen from the side, sub-reniform, much higher behind than in front,
greatest height equal to more than half the length ; posterior extremity very broad
and boldly rounded ; anterior narrower and more flattened ; median third of the
superior margin almost straight, sloping with a steep curve towards the posterior
extremity, and even more steeply and with a distinct sinuation, to the front ;
inferior margin deeply sinuated in the middle. Seen dorsally ; the outline is

102 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

narrow sub-ovate, the anterior extremity compressed and flexuously produced in
a mucronate manner ; posterior rounded off and not produced ; greatest widtli
situated in the middle, and equal to rather more than one-third of the length. End
view, ovate, rounded above, mucronate below. The shell is thin, smooth,
beset with fine, long hairs, yellowish, with cloudings of chestnut brown. Length,
1*2 mm. The left valve is considerably less than the right, its margin being
received within that of the opposite valve for the greater part of its circumference.
General structure of the soft parts as in 0. fabceformis.

This seems to be a distinct and well-characterized species. The one or two
specimens which we have dissected are males, showing verticillate ducts of a
similar type to those of C. Icingsleii and 0 fahceformis. This, together with the
fact that we have as yet found no females, leads to a suspicion that they may
perhaps belong to some species, the females of which are already well known, and
possibly very different in shape.

Habitat. — Baron Loch, near Peebles (D.R.); Loch Alsh, 1^-4^ faths., Mr. T.
Scott (Gr. S. B.); Hairmyres, near East Kilbride; Moor tarns near Grlenluce,
Wigtonshire ; Broomley Lough, Northumberland ; Loch Aber, Kirkcudbrightshire
(A.M.N.).

Distribution. — Norway (Gr. O. Sars, in titt.); Russia (Fischer).

6. Candona kingsleii, Brady and Robertson.
(Plate ix., figs. 19-22; Plate xin., fig. 19.)
1785 ? Cypris detecta, Miiller, Entomostraca, p. 49. Tab. iii., figs. 1-3.

1870. Candona Mngsleii, Brady and Eobertson, Ann. and Mag. Nat. Hist., Ser. nr., vol. vr., p. 17,
pi. ix., figs. 9-12.

Shell of the female, seen from the side, sub-reniform, slightly depressed in
front ; greatest height situated near the middle, and equal to half the length ;
extremities well rounded, the anterior narrower than the posterior ; superior
margin boldly arched ; inferior rather deeply sinuated in the middle ; seen from
above, ovate; greatest width situated in the middle, and rather less than the
height ; pointed in front, narrowly rounded behind. The shell of the male is
more deeply sinuated ventrally ; the dorsal margin is more boldly arched than in
the female, and is slightly excavated towards the front ; seen from above, the
outline is more compressed. Shell thin, fragile, and colourless ; the limbs
of the animal distinctly perceptible through. The antennules are stout, the
joints all short, and nearly equal, the last two scarcely twice as long as broad ;
setae short and stout ; terminal setae of postabdomen stout and rather short, almost

of the North Atlantic and North -Western Europe.

103

falcate. The last two joints of the mandible palp are extremely long and slender.
Length, *9 mm.

This species is widely distributed in the East Anglian district, where we have
found it as follows : Barton, Horsey, Hickling, Wroxham, and Ormesby Broads,
Breydon Water, Dyke at Whittlesea, and in the river Nene at Peterborough (G. S. B.
and D. R.). In Scotland it has been found in the Islands of Lewis and Cumbrae ;
in Loch Lomond ; Loch Echinlinesh, near Dumfries ; St. Jerman Loch and Possil
Marsh, near Glasgow ; Little Loch, near Melston ; in Govan Colliery Dam ; at
Hairmyres, near East Kilbride ; in the Isle of Skye. Also in a pond by the Albert
Memorial, Hyde Park, London (D. R.) ; on the Cardiff Moors, and in a pond at
Sophia Gardens, Cardiff (Mrs. Robertson) ; Whitefield Loch and moor tarns near
Glenluce, Wigtonshire ; Lochaber Loch, Kirkcudbrightshire (A. M. N.) ; Osmere,
Shropshire (G. S. B.)

We refer doubtfully to Cypris detecta (Miiller), as a synonym of the present
species ; but the specimen named 0. detecta by Dr. Baird, and now preserved
in the British Museum, certainly is not Candona kingsleii, neither does it seem to
us to agree altogether with Midler's description of C. detecta.

7. Candona fabceformis (Fischer).
(Plate ix., figs. 1—4.)

1851. Cypris fabceformis, Fischer, Ueber das Genus Cypris, p. 146, pi. iii., figs. 6-16 $ $.
1853. Candona fabceformis, Lilljeborg, De Crust, ex ord. tribus, p. 207 $ $ .

1870. Candona diaphana, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., pi. v., figs.
1-3 ? .

1870. (?) Candona hyalina, iidem, ibidem, p. 18, pi. ix., figs. 5-8, and pi. v., figs. 4-11.

Male. Shell elongated, reniform ; seen from the side, the outline is reniform,
somewhat depressed in front ; greatest height in the middle, and equal to less than
half the length ; extremities boldly rounded ; dorsal margin evenly arched ; ventral
deeply sinuated rather in front of the middle. Seen from above, elongated, sub-
ovate, thrice as long as broad, greatest width in the middle ; extremities acuminate.
End view ovate, pointed below, rounded above. Shell thin and delicate, pellucid,
with yellowish patches ; the posterior portion of the valves marked with three or
four long crescentic lines, which correspond in position with the coils of spermatic
tubes, and run in a concentric manner parallel with the posterior margin of the shell.
Antennules slender, the last two joints three or four times as long as broad ; setss
long and slender. Post-abdominal rami slender, the two terminal setse slender
and gently curved, the longer of the two more than half as long as the ramus ;
the marginal seta short, and about one-third the length of the ramus distant
from its apex. Length of the shell, 1*25 mm.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. P

104 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Female. Shell, seen from the side, elongated, sub-renif orm ; greatest height
situated behind the middle, and equal to less than half the length ; obtusely and
evenly rounded in front, obliquely behind ; superior margin highest at the
posterior third, at that point distinctly angled, and thence sloping almost in a
right line and with a very gentle declivity forwards, very steeply and with a
slightly concave curve backwards ; inferior margin gently sinuated. Seen from
above, compressed, tapering equally and rather suddenly to the extremities, which
are pointed ; sides sub-parallel ; width scarcely equalling one-third of the length.
The hinge-margin of the left valve is suddenly produced towards each extremity
into very conspicuously overlapping curves, the posterior being much larger
than the anterior. Length, 1 mm.

The characters of the form described (toe. cit.), under the specific name hjalina,
are perhaps insufficient: the structure ascribed to the "mucous gland" of the
male was possibly founded on an erroneous interpretation of a distorted specimen
(figs. 5,6); so that until more perfect information on these matters is attainable,
we prefer to regard the specimens previously called hyalina as belonging to
C. fabceformis.

This species has been found as follows : — Craigengam Tarn, Cumbrae ; Hair-
myres Quarry, near East Kilbride ; Lameston Quarries, Ayrshire ; Ballagarey
Meadow, Isle, of Man (D. R.) : ditches on Cardiff Moor (Mrs. Robertson) : Cooly
Banna Lough, Ireland ; River Nene at Peterborough, and Ormesby Broad, Norfolk
(G. S. B. and D. R.); pond near Taymouth Castle and Crosslea, near Paisley,
Mr. T. Scott (G. S. B.).

Distribution. — Sweden (Lilljeborg) ; Russia (Fischer) ; France (Moniez).

8. Candona acuminata (Fischer).
(Plate ix., figs. 9, 10 ; Plate x., figs. 5, 6.)

1851. Cypris acuminata, S. Fischer, Ueber das Genus Cypris, p. 148, pi. iv., figs. 12-16.

1854. Cypris acuminata, Zenker, Monographie der Ostracoden (Archiv fur Naturgesch.), p. 74, pi. ii. D.

Shell, seen from the side, sub-cuneate, somewhat arcuate ; greatest height behind
the middle, not equal to half the length ; anterior extremity widely and very
evenly rounded, point of greatest prominence central; posterior extremity narrow,
not half the height of anterior, sub-truncate, or bluntly rounded ; dorsal margin
gradually and arcuately rising at first, and from behind the eye the rise is still
continued, but here only very slightly until the point of greatest height is
reached behind the middle, thence it rapidly descends with slight arcuation to
the narrow posterior extremity; the ventral margin very irregular, convex at
its commencement in front, then deeply concave, then behind the middle it is

of the North Atlantic and North-Western Europe.

105

convex (here forming the greatest height), and just before its termination there is
again a slight sinuosity. Seen from above, the form is a long ovate ; greatest
breadth central, scarcely exceeding one-third the length ; sides evenly convex,
and the extremities equal and not produced. Surface of valves white, smooth,
polished, their edges beset with fine hairs. Length, 1*2 mm.

For the Norwegian specimens described above, and figured in Plate x., figs. 5,
6, we are indebted to the kindness of Prof. G. O. Sars. In Britain it is a rare
species, the only localities known to us being Hickling Broad, Norfolk (G. S. B.
and D. R.) : Loch Earn Head ; a mill-dam at Wick, Caithness ; Killmuir dam,
Renfrewshire (D. R.) ; and Tarbert, Loch Fyne, Mr. T. Scott (Gr. S. B.). The
figures given in Plate ix., figs. 9, 10, were taken from British specimens,
which we at first supposed to belong to a distinct species, but now refer without
doubt to C. acuminata.

Distribution. — Norway (Gr. 0. Sars !) ; Germany (Zenker) ; Hungary (Orley) ;
Russia (Fischer).

Zenker figures as the male of C. acuminata (PI. I., fig. 23, vide p. 75), a form
which is not unlike our C. rostrata but more elongated, less high in proportion to
its length ; and there can be little doubt that the C. pellucida, Fischer (p. 149,
PI. v., figs. 1—4), but not the C. pellucida, Koch, is the same form.

9. Candona euplectella, Robertson, M. S.
(Plate ix., figs. 7, 8, 8a.)

1880. Candona euplectella, Eobertson, Fresh and Brackish Water Ostracoda of Clydesdale, &c, p. 23
(not described).

Shell very tumid, nearly equal in height and width throughout. Seen from
the side, the outline is sub-quadrate or sub-reniform, height equal to half the length ;
extremities equal and well rounded ; dorsal margin straight ; ventral very slightly
sinuated. Seen from above, broadly ovate, very little wider behind than in front,
scarcely twice as long as broad, extremities broadly rounded, sides sub-parallel.
End view nearly circular. The shell surface is beautifully sculptured with a close
reticulated pattern, like the cells of a honeycomb, and bears also small scattered
tubercles, surmounted by very long, fine, stiff hairs. The polygonal hollows are,
in fact, filled up at distant intervals with solid shell structure, forming bosses,
from the summits of which spring single hairs. The setae of the antennules are
not plumose ; the limbs are small and slender, and have long slender terminal
claws. The few specimens which we have dissected were all males, and probably,
as the shape is alike in all cases, the female has yet to be discovered. Length,
•75 mm.

P 2

106 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Habitat. — This species has been found in Callum's Tarn, Isle of Bute ; Little
Cumbrae; at Lochmaben, in the Year Blind and Broomhill Lochs; and Black
Loch, near Oban (D. R.) ; in pools near Port Glasgow, Mr. T. Scott (G. S. B.).

Specimens of Candona euplectella, in fine condition, and exhibiting in perfect
order the reticulated surface, tubercles and stiff hairs, excel in beauty all other
European freshwater Ostracoda.

10. Candona (?) parabolica (Koch).
(Plate xiii., figs. 28-30.)

1837. Cypris parabolica, Kocli, Deutsclilands Crustaceen, &c, H. xi. 4.

Shell elongated, large, long, smooth, polished, higher before than behind ;
dorsal margin not arched ; ventral margin slightly compressed ; the anterior
and posterior margins with a very fine fringe of hairs, which are, however,
only visible in water. Seen from above, the shell is small, oval, and pointed
before and behind ; pale ochreous yellow, on the back shaded darker ; on the
front edge a small whitish band, on this a darker ochreous yellow, and behind
a lighter, rather transparent line. Sometimes the shell is green, or spotted with
green, the colour arising from a transparent deposit on the surface of the shell.
It cannot swim; its movements in water are only creeping; but it can easily
ascend plants or rough surfaces.

Rather rare in ditches of Germany.

We give in Plate xiii. copies (uncoloured) of Koch's figures of this species, the
only one of the Ostracoda described by him which we have been unable to assign
to recognized forms. The description is slightly abridged from Koch's.

Genus XIII. — Ilyocypris, nov. gen.

(tXv?, mud.)
[Type, Ilyocypris gibba (Ramdohr).]

Shell oblong, with a transverse median depression, coarsely punctate and tuber-
culate. Antennal setae non-plumose, few ; reaching a little beyond the apex of the
terminal claws. Mandible-palp 4-jointed, with a 5-(?)setose branchial appendage.
First pair of maxillae composed of four segments, and a large branchial appendage
bearing numerous terminal and about five reflexed basal setae. Second pair of
maxillae consisting of a conical lobe, which bears numerous short marginal setae, at
the apex four stout plumose setae, and at the base an appendage of four radiating

of the North Atlantic and North-Western Europe.

107

plumose filaments and a bi-articulate process bearing three apical setse, one of
which is plumose. The penultimate joint of the second foot has two marginal setse ;
the last joint three long apical setse, but no claw. Caudal rami ending in two long
and equal claws, and one very short seta, marginal seta long, and attached near
the middle of the ramus.

Ilyocypris gihba (Ramdohr).
(Plate xxii., figs. 1—5.)

1820. (?) Monoculus puber, Jurine, Hist, des Monocles, p. 171, pi. xviii., figs. 1, 2 (non C.puber, Miiller).

1820. Monoculus bistrigatus, idem, ibidem, p. 177, pi. xix., figs. 12, 13 {junior).

1838. Cypris biplicata, Koch, Deutsclilands Crustaceen, H. 21, pi. xvi.

1844. Cypris bistrigata, Zaddach, Syn. Crust. Pruss. Prodr., p. 37.

1847. Cypris sinuata, Fischer, Mem. de l'Acad des Sci. de St. Petersbourg, vol. vi., p. 35, pi. x., fig. 4.

1851. Cypris biplicata, Fischer, Ueber das Genus Cypris, p. 150, pi. v., figs. 5-8.

1853. Cypris bistrigata, Lilljeborg, De Crust, ex ord. tribus, p. 122, pi. xi., figs. 17, 18.

1868. Cypris gibba, Brady, Mon. rec. Brit. Ostrac, p. 369, pi. xxiv., figs. 47-54 ; pi. xxxvi., fig. 2.

1874. Cypris gibba, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 127, pi. xv., figs. 5, 6.

Common in the British Islands.

Distribution. — Sweden (Lilljeborg !) ; Prussia (Zaddach ! and Koch); Switzer-
land (Jurine); Hungary (Orley); Russia (Fischer); France (Moniez !).
Fossil. — Scotland ; England.

Genus XIV. — Pontocypkis, G. 0. Sars.
[Type, P. mytiloides (Norman).]
1. Pontocypris mytiloides (Norman).
Synonyms. — Cy there avena, Norman ; P. serrulata, G. O. Sars.

1858. (?) Bairdia dactylus and var. punctata, Egger, Die Ostracoden der Miocan-Schichten bei Oren-
burg, p. 7, pi. i., figs. 3, 4.

1868. Pontocypris mytiloides, Brady, Mon. rec. Brit. Ostrac, p. 385, pi. xxv., figs. 26-30; pi. xxxvii.,
fig. 1.

1874. Pontocypris mytiloides, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 136, pi. xv., figs. 7, 8.

A widely-distributed and common species, occurring all round the British
coasts, from low-water mark downwards, but most abundantly in the laminarian
zone.

108 Brady and Norman — Monograph of the Murine and Freshwater Ostracoda

Distribution. — Christiania and Flekkefiord, Norway, 3-6 fath. (G. 0. Sars) ;
Oster Fiord and Lervig Bay, Norway (A. M. N.); off Capri, Bay of Naples,
40 fath. (A. M. N.)j Fosse de Cape Breton, 135 fath. (G. S. B.).

Fossil. — Scotland, Norway, Calabria (?).

2. Pontocypris hispida, G. 0. Sars.

1865. Pontocypris hispida, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 16.
1868. Pontocypris hispida, Norman, Last Eeport Dredging Shetland Isles (Brit. Assoc. Rep.), p. 289.
(Not Pontocypris hispida, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. rv., vol. ix.
(1872), p. 61.)

Shell, seen from the side, subtriangular, highest in front, height equal to nearly
half the length ; anterior extremely well rounded, posterior tapered and sub-
acute ; dorsal margin strongly arched, highest at the anterior third, whence it
slopes with a gentle curve to the front, and more steeply towards the posterior
extremity ; inferior margin very slightly sinuated in front of the middle, and
upcurved at the hinder end. Seen from above, the outline is ovate, widest near
the front, nearly three times as long as broad ; extremities sub-acute, tapered
rather abruptly in front, more gradually behind. Valves smooth, or very minutely
punctate, and clothed more or less thickly with very fine adpressed hairs.
Colour, yellowish. Terminal claw of the first pair of feet very long and slender,
exceeding the united lengths of the preceding four joints, and strongly curved at
the apex. Terminal setae of the caudal rami nearly equal. " Copulatory organs
of the male elongated, almost linear, and obtusely rounded at the apex. Eyes
wanting." Length, -8 mm.

The only undoubted British examples of this species were dredged in Birturbuy
Bay, Ireland (G. S. B. and D. R.) ; and Unst Haaf, Shetland (A. M. N.).

Distribution. — Professor G. 0. Sars took it in Christianiafiord, in a depth of
30—50 fathoms, on a clay bottom ; Lervig Bay, Stordoen, Norway (A. M. N.).

The specimens referred by Messrs. Brady and Robertson (toe. cit.) to P. hispida
belong really to P. mytiloides. We now admit the two species as quite distinct.

of the North Atlantic and North -Western Europe.

109

3. Pontocypris acupunctata, Brady.

1868. Pontocypris acupunctata, Brady, Mon. rec. Brit. Ostrac, p. 386, pi. xxiv., figs. 53-56.
1874. Pontocypris acupunctata, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 137, pi. ii., figs.
18, 19.

This is a very rare species. The only additional localities since the publica-
tion of the monograph of 1868, are St. Magnus Bay, Shetland (A. M. N.) ;
Budle Bay, Northumberland; and off Marsden, Durham, 10 fathoms (Gr. S. B.).

Distribution. — Batalden, near Floro, Norway (A. M. N.).

Fossil. — Scotland (Oban).

4. Pontocypris trigonella, Gr. O. Sars.
(Plate xxii., figs. 18-25 ; Plate xxin., fig. 6.)

1868. Pontocypris trigonella, Brady, Mon. rec. Brit. Ostrac, p. 387, pi. xxv., figs. 31-34 ; pi. xxxviii.,
fig. 3.

1874. Pontocypris trigonella, Brady, Crosskey, and Bobertson, Post-tert. Entorn., p. 137, pi. xvi., figs.
26-28.

1880. Pontocypris trigonella, Seguenza, Le formazioni terziarie nelle provincia di Beggio, pp. 288 and
362.

1880. Pontocypris trigonella, Brady, Beport " Challenger," Ostrac, p. 36, pi. xv., figs. ia-d.
1883. Pontocypris trigonella, Seguenza, II Quaternario di Bizzolo, Gli Ostracodi, p. 4.
1885. Pontocypris trigonella, Cams. Prod. Faunas Mediterranean p. 313.

This species is found in moderate abundance all round the coasts of the British
Islands, ranging from low water-mark to 30 fathoms. It is commonest and best
developed in the laminarian zone ; but we have only one record of its occurrence
between tide-marks, at Rockport, Co. Down, where it was taken by the late
Dr. Malcomson.

Distribution. — Norway to Lofoten Islands (Gr. O. Sars); Haakelsund, Kors
Fiord, 3-10 fath. ; and Lervig Bay, Stordoen, 3-25 fath., Norway (A. M. N.);
Messina and Syra (Gr. S. B.), Naples (A. M. N.); Cape Verde Islands and the
Bermudas (G. S. B.).

Fossil. — Scotland, Calabria, Sicily.

110 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Genus XV. — Anchistrocheles, nov. gen.
(ayKL(TTpoi>, a book ; xV^Vi a claw.)
[Type, Anchistrochles fumata, G. S. Brady, M.S.]

Shell much compressed, reniform ; seen laterally, the anterior margin is very
obliquely truncated, the obliquity looking downwards ; dorsal margin arched ;
ventral very deeply sinuated; antennules seven- jointed, the first joint very mucli
longer than all the rest put together, bearing a lash of about ten long setae, which
arise from the last two joints, the rest being bare except that there is one seta
near the apex of the first joint. Antennae five-jointed, ending in a very long
claw, which is much longer than the length of the entire limb, and is bent sharply
at the extremity so as to form a minute hook ; at the sides of the claw are
two setae of rather more than half its length : the penultimate joint has a brush
of three very small setae at the apex, and the second joint bears two setae of
moderate length. The mandible is slender, and rather feebly dentated at the
apex; palp four-jointed, and provided with a small trisetose branchial appendage.
First maxilla four-segmented, and having a setiferous branchial plate of
moderate size. First foot four- jointed, bearing a hooked claw like that of the
antenna, and giving attachment on the first joint to a one- jointed setiferous
appendage, which possibly represents the second maxilla. Second foot four-
jointed, and having a very long, curved, apical claw. Caudal rami rudimentary,
bearing three setae, one of which is very short, the others long and nearly equal.
Copulative organ of the male large and complex.

This description is taken from specimens of an undescribed species collected
by Dr. H. B. Brady, F.R.S., in the Fiji Islands. The Fijian shell, however, in
its very peculiar form so closely resembles the British species, hitherto pro-
visionally placed under Ct/there, that we have no hesitation in referring both
species to the same genus.

1. Anchistrocheles acerosa (Brady).

1868. Cythere acerosa, Brady, Mon. rec. Brit. Ostrac, p. 419, pi. xxxi., figs. 55-58.

No living specimens of this animal have yet been seen. It has been found,
but always very sparingly, in dredgings from Dungeness Bay and off the
Eddystone (G. S. B.) ; by Dr. Norman at Shetland and Plymouth ; in dredgings
by Mr. E. C. Davison off North of Scotland ; and by Mr. Malcomson in the Irish
Sea.

Distribution. — River Scheldt, Holland (G. S. B.).

of the North Atlantic and North -Western Europe.

Ill

Genus XVI. — Aegilloecia, G. O. Sars.

[Type, Argilloecia cylindrical G. O. Sars.]

Valves smooth, elongated, moderately robust, scarcely higher in front than
behind, more or less angulated at the union of the posterior and inferior
margins ; antennules robust, five- jointed, first joint very large and stout,
the rest beset on the lower margins with strong spines, and on the upper
margins, especially in the male, with long setae ; antennas short and thick,
otherwise like those of Pontocypris ; setae of the antepenultimate joint in the
female short, in the male very long, and reaching much beyond the terminal
claws. Mandibles almost as in Pontocypris, the palp, however, having only three
or four setae (" one," Sars) in place of a branchial appendage. Palp of the
second pair of jaws indistinctly three- jointed, bearing several terminal setae
(ending in a single claw, Sars). First pair of feet strong, terminating in two
nearly equal claws ; second pair unlike the first, and almost like those of
Pontocypris ; last joint very short, and bearing about three spines, of which one
is very long and curved. Post-abdominal rami short, attenuated towards the
apices, and with very small terminal claws. Eye wanting.

1. Argilloecia cylindrica, G. 0. Sars.
(Plate x., figs. 28, 29.)

1865. Argilloecia cylindrica, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 18.
1865. Cytherideis oryza, Brady, Trans. Zool. Soc, vol. v., p. 368, pi. lviii., figs. 2a-b.

1868. Pontocypris (?) angusta, Brady, Mon. rec. Brit. Ostrac, p. 387, pi. xxxiv., figs. 43, 44.

1869. Argilloecia angusta, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. rv., vol. iii., p. 11.
1874. Argilloecia cylindrica, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 132, pi. xvi., figs.

29-31.

1885. Argilloecia angusta, Carus, Prod. Faunse Mediterranese, p. 315.

The specimens from Birterbuy Bay, described in the "Monograph" of 1868
under the name Pontocypris (?) angusta, belong to this species.

Additional localities. — In dredgings from Loch Long, the Firth of Clyde, off
Greenock and Largs, Firth of Forth, in the river Ouse, off the Eddystone
Lighthouse, and off St. Mary's, Scilly (G. S. B. and D. R.); Shetland; off
Tarbert, Loch Fyne, 25 fath. ; Salcombe, Devon; Valentia and Roundstone,
Ireland (A. M. N.) ; Irish Sea and Belfast Lough (Malcomson) ; off Seaham and
Marsden, Durham coast (G. S. B.).

TRANS. BOY. DUB. SOC, N.S. VOL. IV., PAET II. Q

112 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Distribution. — Christiania Fiord, 30-50 fath. (G. O. Sars); Oster Fiord, 375
fath. ; off Sartoro, Bergen Fiord, 15-40 fath.; Lervig Bay, 10-25 fath.;
Stocksund, 80-100 fath. ; off Drobak, 30-100 fath. ; all in Norway. Fosse de
Cape Breton, Bay of Biscay, 180-200 fath. (A. M. N.); Hammerfest Harbour ;
River Scheldt, Holland ; Mediterranean ; Tenedos and Besika Bay (Gr. S. B.).

Fossil. — Scotland.

Fam. II.— BAIRDIID.E.

Genus I. — Bairdia, M'Coy.
[Type, Bairdia curta, M'Coy.]

Shell tumid ; seen from the side triangular or sub-quadrate, anterior extremity
broadly rounded, posterior more or less produced. Valves moderately dense,
calcareous, often clothed with stiff hairs, extremities often toothed ; left valve much
larger than the right. Antennules slender; last four joints distinct, and bearing
numerous long, slender setae. Antennae elongated, apical portion attenuated and
bearing two strong terminal claws. Biting portion of the mandible having five
long and strongly aculeated teeth; palp pilose and rather narrow, bearing a
branchial appendage composed of three setae, the foremost of which is very
long. Segments of the maxillae long and narrow, palp exactly like these in
form and size, one- jointed; branchial lamina large, and having at the base a pos-
terior dilatation, broadly rounded, and clothed with very slender non-ciliated setae ;
terminal portion rounded, ovate, bordered with strong plumose setae. Feet succes-
sively larger; similar in build, penultimate joint narrow and elongated; a
large, oblong-triangular branchial lamina affixed to the first pair. Caudal rami not
large, linear, divergent, bearing three strong apical setiform claws, the middle
one elongated ; marginal setae four.

In this generic definition we follow Professor G. O. Sars.

1. Bairdia injlata, Norman.

1865. Bairdia obliquata, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 24.

1868. Bairdia injlata, Brady, Mon. rec. Brit. Ostrac, p. 388, pi. xxvii., figs. 9-17 ; pi. xxxviii., fig. 6.

1874. Bairdia injlata, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 139, pi. xv., figs. 1-4.

Additional localities. — Dredged off Red Cliff, Yorkshire (G. S. B. and D. R.);
Clew Bay, Ireland (A. M. N.) ; Irish Channel, 15-62 fath. ; Belfast Lough,
10 fath. (Malcomson.)

of the North Atlantic and North - Western Europe.

113

Distribution. — Very rare; Oxfiord, Finmark (G. 0. Sars) ; off Sartoro, Bergen
Fiord, 15—40 fath. ; Kors Fiord, 180 fath. ; off Midso Lighthouse, Hardanger
Fiord, 50-100 fath. (A. M. N.)j Fosse de Cap Breton, 45 fath.; Marquis de
Folin (G. S. B.).

Fossil. — Scotland (Oban).

2. Bairdia acanthiyera, Brady.

1868. Bairdia acanthiyera, Brady, Mori. rec. Brit. Ostrac, p. 390, pi. xxvii., figs. 18-21.
1880. Bairdia acanthiyera, Brady, Report, " Challenger," Ostrac, p. 61, pi. ix., figs. 4«-c.
1883. Bairdia acanthiyera, (?) Seguenza, II Quaternario di Rizzolo II. Gli Ostracodi, p. 17.

The only known British localities are those recorded in the " Monograph,"
namely, Devonshire and the Channel Islands.

Distribution. — Off St. Vincent, Cape Verde Islands, 1070 and 1150 fath.,
"Challenger » Exped. (Gr. S. B.).

Fossil. — (?) Rizzolo, Sicily.

3. Bairdia subcircinata, n. sp.

1880. Bairdia formosa, Brady, Report, " Challenger," Ostrac, p. 52, pi. x., figs. 1 «-c.

(Not 1868, B. formosa, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ii., p. 221, pi. xiv.,
figs. 5-7.)

Shell, as seen from the side, triangular, all the angles broadly rounded off ;
height greatest in the middle, and equal to three-fourths of the length ; the dorsal
margin is excessively arched, and somewhat gibbous in the middle ; the ventral
straight or rather convex ; anterior extremity broadly rounded, posterior narrower,
slightly produced below the middle. Seen from above the outline is very broadly
ovate, the greatest width being situated in the middle, and equal to more than
half the length ; extremities obtuse, sub-mucronate. The end view is broadly
ovate, the height considerably greater than the width. In well-developed adult
specimens the surface is slightly punctate, and is beset with numerous little
tubercular or papillif orm eminences ; the left valve bears in front and at the infero-
posteal angle a series of five to seven spines ; the right valve is fringed along its
anterior margin with a considerable number — twelve or more — of small blunt
teeth. Young specimens have the shell quite smooth and destitute of marginal
teeth. Length, 1*55 mm.

In the report on the " Challenger" Ostracoda, the specimens there referred to
Bairdia formosa were noted as differing from the Mediterranean type ; but after
an examination of the more recent dredgings of the " Talisman" (see Appendix)

Q 2

lit Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

we no longer doubt that the two forms are specifically distinct, and we propose
for the Atlantic species the name suhcircinata.

The most important distinctive characters are, that both extremities are
spinous, the left valve having in front a series of about seven marginal spines, and
the right a closely-set row of short blunt teeth. At the posterior extremity the
upward slope of the ventral margin is beset with numerous small spines (usually
smaller than represented in the " Challenger," loc. eit., plate x., fig. 1 b) ; and in the
living condition the shell is clothed with strong dark-brown hairs, and marked
with distant, rather coarse, circular puncta ; posterior margin not at all beaked.

Distribution.— North Atlantic, lat. 38° 11' N., long. 27° 9' W., 900 fath. ; South
Atlantic, lat. 8° 37' S., long. 34° 28' W., 675 fath. ; and off North Brazil, lat.
9° 5' S., long. 34° 49' W., 350 fath. ; South Pacific, one or two doubtful examples,
lat. 5° 26' S., long. 133° 19' E., 580 fath. ; all "Challenger" Exped. (G. S. B.) ;
North Atlantic, lat. 56° 1' N., long. 34° 42' W. ; "Valorous" Exped., 1875,
Stat. 13 (A. M. N.).

4. Bairdia angulata, Brady.

1870. Bairdia angulata, Brady, Les Fonds de la Mer., vol. i., p. 199, pi. xxvii., figs. 11, 12.
1880. Bairdia angulata, Brady, Beport, " Challenger," Ostracoda., p. 59, pi. xi., figs. 5 a-d.

Shell oblong, compressed ; seen from the side sub-reniform, scarcely twice as
long as high ; extremities well and evenly rounded, the anterior bearing about the
middle few (four or five) short, broad teeth ; the posterior armed below the middle
with six or eight nearly similar teeth ; dorsal margin very slightly arched ; ventral
straight, except that near the front at its junction with the anterior border, it is
produced downwards into a conspicuous angular prominence. Seen from above,
the outline is about thrice as long as broad, compressed, with parallel sides and
tapering acuminate extremities. End view ovate, compressed ; width scarcely
equal to half the height. Surface of valves smooth or finely punctate. Length,
•9 mm.

Distribution. — Dredged by " Challenger," off the Azores, lat. 38° 37' N., long.
28° 30' W., 450 fath. ; South Atlantic, lat. 47° 48' S., long. 74° 48' W., 120 fath. ;
and in Torres Straits, 155 fath. The original specimens were taken at Halt Bay,
in the Straits of Magellan (G. S. B.).

of the North Atlantic and North-Western Europe.

115

5. Bairdia victrix, Brady.

1869. Bairdia victrix, Brady, Les Fonds de la Mei\, vol. i., p. 152, pi. xviii., figs. 17, 18.
1880. Bairdia victrix, Brady, Eeport, " Challenger," Ostracoda, pi. 56, p. x., figs. 5a-d.

Shell tumid, gibbous; seen from the side sub-triangular, height equal to
rather more than two-thirds of the length ; anterior extremity rounded ; posterior
obliquely truncate and produced into a prominent obtuse beak ; dorsal margin very
boldly arched ; ventral more or less convex, and often irregularly sinuous towards
the posterior extremity ; the margins of the right valve are often beset at the two
extremities with numerous short obtuse teeth. Seen from above, the outline is
broadly ovate, more than twice as long as broad, widest in the middle ; anterior
extremity sub-acuminate, posterior broadly mucronate. End view ovate, widest
below, height almost one-third greater than the width. Surface of the shell
smooth, sometimes sparingly punctate, and (especially towards the hinder end)
having a few scattered, rigid hairs. Length, 1*6 mm.

Distribution. — Dredged by " Challenger " in North Atlantic, in the neighbourhood
of the Azores, lat. 38° 11' N., long. 27° 9' W., 900 fath. ; and lat. 38° 37' N., long.
28° 30' W., 450 fath. Also off North Brazil, 350 to 675 fath. ; off Kerguelen
Island 120 fath. ; off Sydney, Australia, 410 fath. ; and to the north of Tristan
d'Acunha, 1425 fath. The first-described specimens were from Colon- Aspin wall,
and it has also been taken at Cuba (G. S. B.) ; North Atlantic, lat. 56° 1' N., long.
34° 42' W., 690 fath., " Valorous" Exped., 1875. Stat. 13 (A. M. N.).

6. Bairdia crosskeiana, Brady.
(Plate x., figs. 3, 4.)

1865. Bairdia crosskeiana, Brady, Trans. Zool. Soc, vol. v., p. 366, pi. lvii., figs. 10 a-d.

1880. Bairdia crosskeiana, Brady, Report " Challenger " Ostracoda, p. 58, pi. ix., figs. 3 a-c.

1884. Bairdia crosskeiana, Seguenza, II Quaternario di Rizzolo II. Gli Ostracodi, p. 15.

1885. Bairdia crosskeiana, Carus, Prodr. Faunae Mediterranean, p. 316.

Shell elongated, compressed, greatest height equal to about half the length,
and situated near the middle ; seen laterally, the outline is sub-ovate or sub-
triangular, wider in front than behind ; anterior extremity obliquely rounded,
angulated at its junction with the dorsum, lower angle obliterated and forming a

116 Brady and Nokman — Monograph of the Marine and Freshwater Ostracoda

wide curve continuous with the ventral margin ; posterior narrow and tapered,
sub-acute and more or less squamously dentated below; dorsal margin well
arched, slightly sinuated in front ; ventral nearly straight. Seen from above the
outline is lozenge-shaped, more than twice as long as broad ; near the front taper-
ing rather abruptly forwards, gradually and with a gentle curve towards the
posterior extremity ; anterior extremity obtuse ; posterior pointed ; surface smooth,
closely set with minute punctations. Length, 1*3 mm.

Distribution. — Fosse de Cap Breton ; two miles from the mouth of the Adour,
Marquis de Folin (G. S. B); Fosse de Cap Breton, 30-60 fath., and 180-200 fath.
(A. M. N.); Tongatabu ; Nares' Harbour, Admiralty Islands, 16 fath. ; Honolulu,
40 fath., "Challenger" dredgings (G. S. B.); Messina (Seguenza).

Fossil. — Sicily (Seguenza).

The southern form of this species, as shown in the " Challenger " specimens, is
somewhat more slender, and the outline, as seen from above, is more distinctly
angular and hastate.

7. Bairdia obtusata, G. O. Sars.

1868. Bairdia obtusata, Brady, Mon. rec. Brit. Ostrac, p. 390, pi. xxxiv., figa. 22-25.
Additional locality. — Irish Channel, 60 fath. (Malcomson).

Distribution. — Flekkefiord, West Norway, 80—90 fath. (G. O. Sars); Solems
Fiord by Floro, 30-60 fath. ; off Midso Lighthouse, Hardanger Fiord, 50-210 fath. ;
Stoksund, 126 fath., all on the West Norwegian Coast (A. M. N.).

Fossil. — Calabria (Seguenza).

8. Bairdia complanata, Brady.
(Plate xiii., figs. 20-26.)

1868. Bairdia complanata, Brady, Mon. rec. Brit. Ostrac, p. 390, pi. xxxiv., figs. 1-4.

1880. Bairdia complanata, Seguenza Le format, terz. Reggio, p. 288 (" var. sinuata ").

1883. Bairdia complanata, Seguenza, II Quaternario di Rizzolo II., Gli Ostracodi, p. 17 (" var. sinuata ").

1885. Bairdia complanata, Carus Prod. Faunae Mediterraneas, p. 317.

Additional localities. — Five to eight miles east of Balta, Shetland, 40—50 fath. ;
Loch Fyne (A. M. N.).

Distribution. — Abundant in certain localities on West Norway coast ; south side
of Kors Fiord, 180 fath. ; off Sartoro Bergen Fiord, 15-40 fath. ; off Midso Light-
house, Hardanger Fiord, 50—100 fath. (A. M. N.), var. sinuata, Messina (Seguenza).

Fossil. — Var. sinuata, Rizzolo, Sicily, and Calabria (Seguenza).

of the North Atlantic and North- Western Europe.

117

Prof. G. 0. Sars has recently suggested* that Bairdia complanata, and B. obtusata
probably belong to the genus Bythocypris. The anatomy of Bythocypris is only
very imperfectly known, the drawings given in the Report of the " Challenger "
Expedition being founded on an examination of one or two mutilated specimens ;
but so far as we can at present ascertain, Bairdia complanata seems to be inter-
mediate in its characters between the two genera ; the caudal rami, antennules,
and mandibles agreeing pretty closely with those of Bairdia, while the shell and
antenna? approach those of Bythocypris. For the present it seems best to leave the
species in the genus Bairdia.

Genus II. — Macrocypris, Brady.
[Type, Macrocypris minna (Baird).]
1. Macrocypris minna (Baird).

1868. Macrocypris minna, Brady, Mon. rec. Brit Ostrac, p. 392, pi. xxvii., figs. 5-8 ; pi. xxxviii., fig. 4.
1880. Macrocypris minna, Seguenza, Formaz. terziarie nella provincia di Eeggio, p. 191.
1883. (?) Macrocypris minna, idem, II Quaternario di Bizzolo II. Gli Ostracodi, p. 10.

The only British locality of this species is Shetland, where a single specimen
was dredged by M 'Andrew forty years ago, and a second by A. M. N. on the
Outer Haaf, in 1861.

Distribution. — Christiania Fiord, 20—50 fath., and thence to the Lofoten Islands
(G. O. Sars); Drobak, Christiania Fiord, 30—100 fath. ; Oster Fiord, north of
Bergen, 50-375 fath. ; Lervig, Stordoen, 25 fath. (A. M. N.) ; Bay of Biscay,
Marquis de Folin (G. S. B.).

Fossil. — Calabria ; (?) Rizzolo, Sicily (Seguenza).

2. Macrocypris angusta (G. O. Sars).

(Plate ix., figs. 17, 18.)

1865. Bairdia angusta, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 22.

Shell greatly elongated, narrow, and produced at the extremities ; seen from
the side, both ends are much drawn out, and finally terminate in spine-points,
hinder extremity the more produced ; greatest height in front of the middle,
less than one-third the length ; dorsal margin evenly arched, except near the
posterior extremity, where there is a slight concavity ; ventral margin sinuated in

* Nye Bidrag til Kundskaben om Middelhavets Invertebratfauua, rv., Ostracoda Mediterranea p. 117.

118 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

front of the middle, behind this nearly straight with a slight tendency to convexity.
Seen from above, greatly elongated, and very narrow ; greatest breadth nearly
central, a little less than the height, equally attenuated towards the very acute
extremities. Surface of valves white, smooth, and polished ; a few short, scattered
hairs at the extremities. The right valve is somewhat larger than the left, which
closes partially within it, especially at the posterior extremity. Length, 2 mm.

Sars thus describes the animal: — "Membra animalis pallide flavescentia.
Antennae quam in M. minna magis elongata ; superiores longius setiferse, articulo
tertio valde elongato, sequentibus 3 junctis longiore, inferiorum articulus ante-
penultimus antecedente multo longior, ungues terminales breves et insequales.
Aculei palpo maxillarum 2cli paris inhserentes non dentatae. Pedum primi paris
articulus secundus sequentibus duobus junctis, longitudine circiter sequalis, ultimus
brevissimus ungue unico perlongo et curvato instructus. Pedum ultimi paris
unguis terminalis in margine modo altero dentatus. Rami postabdominales
appendices duas sat elongatas, mucroniformes, obsolete biarticulatas ad apicem
acuminatam leviter supra curvatas formantes. Organa copulationis maris forma
singulari, aviculariis Polyzoum simillima, processibus rostriformibus duobus mobi-
libus sibique applicantibus instructa."

Distribution. — Frequent in the Christiania Fiord, and abundant near Trondhjem
(Gr. O. Sars); off Midso Lighthouse, Hardanger Fiord, 50—100 fath. ; Drobak,
Christiania Fiord, 100 fath. (A. M. N.). Only as yet known in Norway.

This species differs somewhat from the typical Bairdice in the conformation of
the antennules and caudal rami ; but we have not at our disposal materials for a
complete investigation of its anatomy.

3. Macrocypris siliquosa, Brady.
Macrocypris siliquosa, Brady, Les Fortds de la Mer., vol. iv., p. 194, pi. xiv., figs. 1-3.

Shell elongated, compressed ; seen from the side, the height is everywhere
nearly equal, being about two-fifths of the length ; anterior
extremity evenly rounded, posterior forming with the dorsal
margin a continuous curve, and joining the ventral margin
at an acute angle ; dorsal margin evenly and very slightly
arcuate ; ventral almost straight, slightly convex behind the
middle ; seen from above, the outline is a compressed oval,
thrice as long as broad and widest in the middle, only
slightly tapered towards the extremities, which are moderately
broad. The right valve is larger than the left, overlapping

both on the dorsal and ventral margins. Surface perfectly smooth and white.
Length, 1*55 mm.

of the North Atlantic and North -Western Europe,

119

The types of this species were found by the Marquis de Folin in one of the
dredgings of the " Talisman," from a depth of 932 metres, in lat. 23° N., long.
16° 27' W. (G. S. B.) We have also found a broken fragment of a valve,
belonging to the same species, in one of the " Porcupine " dredgings from
lat. 56° 11' N., long. 10° 56' W., depth 1366 fath. (A. M. N.).

Genus III. — Bythocypeis, Brady.
[Type, Bythocypris bosquetiana (Brady).]

Shell thin and fragile, smooth, reniform or subreniform ; left valve much
larger than the right, which it overlaps both on the dorsal and ventral margins.
Antennules short and stout, six-jointed, the first two joints very large, the re-
mainder small, and bearing numerous long setae. Antennae also short and stout,
five-jointed, having no " hyaline-vesicle," the second and fifth joints about twice as
long as the rest, scarcely at all tapered towards the apex, and terminating in
about six curved setae, one of which is much stouter than the others. Mandibles
armed with numerous strong serrated apical teeth, and furnished with a well-
developed four- jointed and setiferous palp, the first joint of which bears a rudi-
mentary branchial appendage, consisting of a single stout seta. One pair of jaws
only (?), consisting of four setiferous digits, and a large branchial appendage,
which is divided into two portions, the upper portion ovate, and bearing ten setae,
the lower narrow, biarticulate, and provided with five slender setae. Two
pairs (?) of feet, the first having a single curved terminal claw, and about three
short marginal setae ; the second rudimentary, consisting of a single small joint,
with two stout setae. Post-abdominal rami of moderate size, curved, and armed
at the apex with one long and one short curved seta.

Bythocypris was described by Professor Brady in his "Challenger" Report,
to which we refer for further observations of the genus and illustrations of the
animal.

The type species, B. reniformis (Brady), we are now satisfied is the species
described long before (from a young shell) as Bairdia bosquetiana (Brady).

TRANS. ROY. DUB. SOC, N.9. VOL. IV., PART II.

120 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Bythocypris bosquetiana (Brady).
(Plate xiv., figs. 34, 35, junior.)

1865. Bairdia bosquetiana, Brady, New and imperfectly known species of marine Ostracoda, Trans.

Zool. Soc, vol. v., p. 364, pi. lvii., figs. 5 a-c { junior).
1880. Bythocypris reniformis, Brady, Rep. " Challenger," Ostracoda, p. 46, pi. v., fig. 1 a-b.

Shell reniform ; seen laterally, the greatest height is situated in the middle,
and equal to more than half the length ; extremities rounded, the anterior rather
broader than the posterior ; ventral margin sinuated in the middle, dorsal
boldly and evenly arched. Seen from above, the outline is narrowly ovate, about
thrice as long as broad, and widest in the middle, tapering evenly to the ex-
tremities, of which the anterior is pointed, and the posterior more obtusely
pointed. End view ovate, the width equal to about two-thirds of the height.
The left valve is more rounded in contour, and is also much more strongly arched
dorsally than the right valve. The hinge-margins overlapping along almost the
entire length of the left valve, the lower margin also forms a curved flange,
which overlaps the right valve in the middle of the ventral aspect. The shell is
thin, smooth, and homogeneous in structure, but marked with irregularly-
scattered translucent spots ; muscle spots arranged irregularly near the centre of
the valves. Length, 1*3 mm. in the "Challenger" specimens; but the Atlantic
example is considerably smaller.

Distribution. — Atlantic Ocean, 470 fath. ; Commander Dayman's soundings ;
off Culebra Island, West Indies, 390 fath. ; off North Brazil, 350-675 fath. ; off
Prince Edward's Island, 50-150 fath. ; and off Moncceur Island, Bass' Strait, 40
fath. ; all from " Challenger" dredgings (Gr. S. B.).

The reniform contour and very marked overlapping of the one valve over the
other on the dorsal margin are points by which this species may be readily
distinguished.

\_Goniocypris mitra, B. and R. — The shell described under this name in the
"Annals and Magazine of Natural History" for July 1870 is not an Entomos-
tracan, but the fry of Anodonta cygncea.

The fry of Anodonta is described by Dr. Jeffreys in his work on the British
Mollusca, vol. i., p. 43].

of the North Atlantic and North -Western Europe.

121

Fam. III. — DARWINULIDiE.
Genus Darwinula, Brady and Robertson.*

Polycheles, Brady and Robertson ; Darioinella, Brady and Robertson (names

pre-occupied.)

[Type, D. stevensoni, Brady and Robertson.]

1870. Polycheles, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 25.

1872. Darivinella, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. ix., p. 50.

1874. Darivinella, Brady, Crosskey, and Robertson, Post.-tert. Entorn., p. 140.

1885. Darivinella, Brady and Robertson, Quart. Journ. Geol. Soc.

Shell smooth, thin, and fragile. Carapace oblong, higher behind than in front ;
lucid spots ten to twelve in number, linear-oblong or wedge-shaped, arranged in a
subradiate manner in front of the centre of the valve. Seen from the side, com-
pressed, oblong, subovate. Seen from above, ovate, acuminate in front, obtusely
rounded behind. Valves unequal, the right much larger than the left. Antennules
very short, six-jointed, and stout, strongly armed with short and stout curved
setae. Antennae four- jointed, and bearing four or five strong terminal claws;
entirely destitute of poison gland or urticating setae, the place of which is occupied
by a single curved seta of moderate length. Mandible broad, truncated at the distal
extremity, which is provided with six or seven small spiniform teeth ; palp three-
jointed, its basal joint very wide and fringed with several curved setae, bearing
also a small lamina, fringed with branchial filaments ; second joint long,
slender, nearly four times as long as broad, slightly curved and dilated at the
distal extremity, where it bears one long and two small setae ; terminal joint more
slender, about two-thirds of the length of the foregoing, and bearing at the truncate
apex about six slender curved spines. First maxilla divided into four short seti-
ferous segments, and bearing a very large oblong palp, which is fringed with about
twenty -four long branchial filaments, and has also four other long setae at its base.
Second maxilla simple, short, and broad, truncate at the apex, and fringed on the
distal margin with several slender spine-like hairs, bearing also a large, three-jointed,
pediform palp, and an ovate branchial appendage of moderate size. Two j)airs of
feet of moderate size, five- jointed ; second pair much the longest, and having the

* The generic term Darioinella having been previously appropriated by Fritz Miiller for a genus of
horny sponges was withdrawn in favour of Danvinula ; see T. Rupert Jones, on " the Ostracoda of the
Purbeck Formation," Quarterly Journal of the Geological Society, August, 1885.

R 2

122 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

last joint armed with one long and two small curved setae ; first three joints of
nearly equal length ; fourth and fifth, respectively, about one-half and one-third as
long as the preceding. Abdomen ending in a short conical process. Copulative
organs of the male of complex structure, the basal portion (on each side) consisting
of a subrhomboidal acuminate lamina, the apical portion of an irregularly-shaped
plate produced laterally into an aliform process, and on the distal margin into a
short, strong hook. Female probably viviparous.

Darwinula stevensoni, Brady and Robertson.
(Plate x., figs. 7—13 ; plate xm., figs. 1—9 ; plate xxiii., fig. 5.)

1870. Polycheles stevensoni, Brady and Kobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 25,

pi. vii., figs. 1-7 ; and pi. x., figs. 4-14.
1870. Argillcecia aarea, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 16,

pi. viii., figs. 4, 5.

1872. Darwmella stevensoni, Brady and Robertson, ibid., ser. iv., vol., ix., p. 50.
1874. Danvinella stevensoni, Brady and Robertson, ibid., ser. iv., vol. xiii., p. 117, pi. v., figs. 8-10.
1874. Danvinella stevensoni, Brady, Crosskey, and Robertson, Post.-tert. Entom., p. 141, pi. ii., figs.
13-17.

Shell of the female, as seen from the side, oblong, depressed in front,
height equal to more than one-third of the length ; extremities obliquely rounded,
anterior narrowed, posterior broad and obtuse : superior margin nearly straight, curv-
ing downwards in front of the middle ; inferior slightly sinuated in the middle. Seen
from above, ovate-acuminate, widest near the posterior extremity ; greatest width
about equal to the height ; posterior margin indented in the middle at the junction
of the two valves. End view nearly circular. Shell of the male somewhat more
compressed ; when seen from above, having the greatest widtli near the middle.
The right valve much overlaps the left, especially in the middle of the ventral
margin. Length, *8 mm.

This is perhaps the most characteristic Entomostracan of the East Anglian Fen
district, where it is widely spread, and often occurs in considerable abundance.

The following is a complete list of habitats, so far as known to us :— Whittlesea
Dyke ; Lake Lothing, and Breydon Water ; Rivers Nene, Cam, Ouse, Deben ;
Wroxham, Barton, Horsey, Hickling, Somerton, Ormesby, and Oulton Broads,
Loughs Inagh, Corrib, Agraffard, Arddery, and Nascrahoge in Connemara (G. S. B.
and D. R.) ; Marbury Mere, Blackmere, and Osmere, Shropshire ; White Loch and
Borean Loch, Kirkcudbrightshire (G. S. B.); Broomhill Loch, Dumfriesshire,
Mack Loch, near Oban ; Canal at Cardiff (D. R.) ; Loch Fell, Wigtonshire,
Lochs Aber and Ruter, Kirkcudbrightshire (A. M. N.).

of the North Atlantic and North -Western Europe.

123

Distribution. — River Scheldt, Holland (G. S. B.); Lac d'Ossegor, Cap Breton,
S. W. France; Marquis de Folin (G. S. B.); Bedestresser See, N. Germany;
S. A. Poppe (G. S. B.).

Fam. IV. — CYTHERIDiE.

Genus I. — Metacypris, Brady and Robertson.

(Ann. and Mag. Nat. Hist., ser. iv., vol. vi. (1870), p. 19.)

[Type, M. cordata, Brady and Robertson.]

Shell moderately strong and thick. Seen from the side, the outline is sub-
rhomboidal, rounded in front, and obscurely angular behind ; the posterior portion
of the hinge-margins produced angularly. Seen from above, heart-shaped in the
female, broadly ovate in the male; ventral surface deeply inpressed along
the central and posterior portions of the median line. Hingement formed on
the right valve by a laminated angular projection anteriorly, posteriorly by a
strong rectangularly-produced flange, from which projects a single sharply-cut
tooth, the flange itself being continued round the posterior margin of the valve ;
on the left valve by a deep sulcus behind, and a shallower one in front. Except in
front, and at the supero-posteal angle, the margins of the valves are incurved con-
siderably, so that the actual contact-margins embrace a much smaller area than
that of the entire shell. The right valve is larger than the left. Animal closely
resembling Cythere.

Metacypris cordata, Brady and Robertson.
(Plate xiii., figs. 10-17; and Plate xiv.,figs. 3-12.)

1870. Metacypris cordata, Brady and Kobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p 20, pi. vi.,

figs. 1-9.

1871. Metacypris cordata, idem, ibidem, vol. ix., p. 51, pi. ii., figs. 9, 10.

Shell of the female excessively tumid and depressed. Seen from the side,
subovate or subrhomboidal ; highest in the middle ; height equal to more than
half the length ; anterior extremity well rounded, posterior obscurely angular ;
superior margin gently arched, produced at its posterior extremity into an angular
process corresponding in position to the posterior hinge- joint; inferior margin

124 Brady and Nokman — Monograph of the Marine and Freshwater Ostracoda

distinctly convex, curving upwards behind, in front rather deeply and abruptly
sinuated at its junction with the anterior margin. Seen from above, the outline
is heart-shaped, pointed in front, posterior extremity broadly rounded and
indented at the junction of the two valves; greatest width situated behind the
middle, much greater than the height, and equal to about five-sixths of the length ;
the lateral margins are boldly curved and somewhat sinuous in the anterior part
of their course. End view subreniform, depressed ; sides excessively convex ;
superior margin arched and slightly indented in the middle, inferior deeply
sinuated in the middle, where, however, it is encroached on by the downwardly
produced anterior margin.

The shell of the male differs in having an almost straight dorsal line, a very
wide, obliquely truncated postero-dorsal angle, and in the ventral margin being
rounded off behind with a bold curve. Seen from above, the outline, instead of
being cordate, is ovate, and widest in the middle, the posterior extremity being
narrowed and rounded off. Surface closely set with small, rounded impressions,
which on the ventral surface are arranged in longitudinal rows, and tend to run
into furrows ; ventral surface deeply sulcate along the greater portion of the
median line. Colour green, with irregular blotches of darker green, or black.
Length "5 mm.

Antennules slender, six-jointed ; the third, fourth, and sixth joints nearly
equal in length ; fifth slightly longer ; last joint bearing four slender setae,
two of which are moderately long ; fourth and fifth joints also bearing two or
three slender apical seta?; antennas, jaw, and feet as in Ci/ there ; the mandible-palp,
however, short, indistinctly jointed, and bearing an appendage composed of three
segments, the two larger of which bear each two setae, the smaller one seta;
abdomen ending in two short curved setae.

This remarkable species was first found in several gatherings from the East
Anglian Fen district, viz. Rivers Nene and Cam, Wroxham and Barton Broads,
and Breydon Water (G. S. B. and D. R.). All the specimens from these
localities, however, were only dead shells. More recently we have been fortunate
enough to find perfect animals in Coolbareen Lough, Co. Mayo, and Lough
Aubwee, near Galway, from which the anatomical characters have been gathered.
All these specimens were females ; but in some later gatherings from Ellesmere
Canal, Osmere, and Colmere, Shropshire (G. S. B.), we have found a few males.

Disrtibution. — In dredged sand from the River Scheldt, Holland (G. S. B.).

of the North Atlantic and North -Western Europe.

125

Genus II. — Cythere, Miiller.
[Type, Cythere lutea, Miiller.]
1. Cythere lutea, Miiller.

Synonyms : Cythere reniformis, Baircl ; C. setosa, Brady.

1868. Cythere lutea, Brady, Mon. rec. Brit. Ostrac, p. 395, pi. xxvii., figs. 47-58; pi. xxxix., fig. 2.
1868. Cythere viridis, Brady, Mon. rec. Brit. Ostrac, p. 397, pi. xxviii., figs. 40, 41, and 50-59 ;

pi. xxxviii., fig. 8 (but not Cythere viridis, Miiller), (junior).
1874. Cythere lutea, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., Scotland, p. 148,
pi. iii., figs. 1-6.

1874. Cythere viridis, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., Scotland, p. 147'

pi. iii., figs. 26-28 [junior).
1888. Cythere lutea, Dahl, Die Cytheriden der Westlich. Ostsee, p. 9, pi. i., figs. 1-12, 27-29.

Cythere lutea occurs commonly all round the coasts of the British Islands in
the littoral and laminarian zones, extending to considerable distances up river
estuaries, such as those of the Stour and Deben, in Suffolk. When living amongst
algae, it is usually deeply coloured in the central portion of the shell with a
yellowish or reddish-brown incrustation ; but specimens dredged from greater
depths are of a uniform dirty-grey tint.

Distribution. — Norway, frequent (G. 0. Sars) ; Drobak ; Lervig, in Hardanger
Fiord; Bukken, Kors Fiord, Norway. Holstenbourg and Godhavn Harbours,
Greenland; Davis Strait, lat. 76° 17' N., long. 62° 21' W., just below low-water
mark; "Valorous" Exped. (A. M. N.); Mediterranean; Iceland; Hammerfest
Harbour; Gulf of St. Lawrence (G. S. B.).

Fossil. — Scotland, Belfast, Iceland, Canada, Norway.

It will thus be seen that this very common British Cythere has a most
extensive range both at the present and in the post-tertiary epoch.

126 Bkady and Norman — Monograph of the Marine and Freshwater Ostracoda

2. Cythere pellucida, Baird.
(Plate xiv., figs. 13-15.)

1850. Cythere pellucida, Baird, British Entomostraca, p. 173, pi. xxi., fig. 7 (e typis).
1865. Cythere castanea, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 32.

1868. Cythere castanea, Brady, Mon. rec. Brit. Ostrac, p. 398, pi. xxviii., fig. 27; and pi. xxxviii.,

fig- 6.

1869. Cythere castanea, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. in., pi. xix., figs.

15-18.

1874. Cythere castanea, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 143, pi. xiii.,
figs. 8-11 ; and pi. hi., fig. 25.

For habitats of this species, see under Cythere castanea, in Brady's monograph.

The type specimens of Dr. Baird's Cythere pellucida from Boston are in Dr.
Norman's collection, and they are not the species which has been regarded by
authors as C. pellucida, but are the form named by Sars, C. castanea. The ordinary
specimens of the latter form are smaller than the former (i. e. the Cythere confusa
of this memoir) ; but Dr. Baird's Boston specimens are smaller still, though
decidedly the same as C. castanea, with which they agree in all characters. The
transverse furrow, which is neither referred to nor figured by Baird, is as distinct
in these specimens as usual.

This is essentially a brackish-water species, and is found all round the coasts
of Great Britain and Ireland in salt marshes and estuaries, and in rivers as far
as, or even further than, the tidal influence extends. We have found it in
places as far inland as Whittlesea, and in several of the Norfolk and Suffolk
Broads (G. S. B. and D. R.). It occurs also not uncommonly in dredgings from
shallow water up to 4 or 5 fath., and less commonly up to 30 fath.

Distribution. — Christiania, Norway (G. O. Sars) ; Hollingspollen, Drobak ; and
Bergen, Norway; Fosse de Cap Breton, Bay of Biscay, in 180-200 fath., but
probably washed into that deep trough from shallow water, as it is usually an
estuarine and shallow- water species (A. M. N.) ; Rivers Scheldt and Maas,
Holland (G. S. B.); Naples (A. M. N.).

Fossil. — Scotland, Cardiff (New Dock Basin).

of the North Atlantic and North-Western Europe.

127

3. Cythere co?ifusa, nom. nov.
(Plate xiv., figs. 16-18.)

1865. Cythere pellucida, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 31 (but not of Baird).

1868. Cythere pellucida, Brady, Mon. rec. Brit. Ostrac, p. 397, pi. xxviii., figs. 22-26, 28.

1869. Cythere pellucida, Brady and Robertson, Ann. and Mag. Nat. Hist.,ser. rv., vol. iii., pi. xix., figs.

10-12.

1874. Cythere pellucida, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 142, pi. iii.,
figs. 20-24.

1884. Cythere pellucida, Cams, Prod. Faunae Medit., p. 294.

This is more strictly a marine species than C. pellucida, and is not so univer-
sally found in tidal or brackish waters, though we have records of its occur-
rence in many such situations on the Northumberland coast, as well as in the
Rivers Humber, Ouse (Yorkshire and Norfolk), and Thames ; at Whittlesea and
in Breydon Water, Norfolk. In deep water all round our coasts it is found more
abundantly than C. pellucida.

Distribution. — Christiania to Finmark (Gr. O. Sars) ; Haakelsand, in Kors Fiord ;
Lervig Bay; Drobak ; all in Norway (A. M. N.) ; Iceland; Holland, River
Scheldt (Gr. S. B.); Fosse de Cap Breton, Bay of Biscay (A. M. N.) ; Messina
(Seguenza), Mediterranean, St. Malo, Syra, Smyrna (Gr. S. B.); Gulf of St.
Lawrence (Gr. S. B.); Naples (A. M. N.).

Fossil. — Scotland ; Ireland, at Belfast and Portrush ; Norway ; Sicily.

4. Cythere porcellanea, Brady.
(Plate xiv., figs. 22, 24.)

1869. Cythere porcellanea, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 47, pi. vii., figs. 1-4
( junior).

1869. Cythere porcellanea, Brady and Robertson, ibid., p. 367, pi. xix., figs. 1-4.

1869. Cythere propinqua, G. 0. Sars, Undersogelser over Christianiafjordens Dybvandsfauna, p. 57,
and note, p. 58.

1874. Cythere porcellanea, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 144, pi. xiii.,
figs. 1, 2.

Shell of female, seen from the side, flexuous, reniform, highest in the middle,
greatest height equal to rather more than half the length ; anterior extremity
evenly, posterior obliquely, rounded ; superior margin evenly arched, inferior
deeply sinuated in the middle; postero-superior angle well marked. Seen from
above, ovate, widest in the middle, sharply poin-tect, in front, rather more obtusely

TRANS. EOY. DUB. SOC, N.S. VOL. IV., PAET II. fc>

128 Brady and Norman — Monograph of the Marine and Freshwater Osiracoda

behind ; width somewhat less than the height. Surface smooth and polished,
marked (usually behind the middle) with a few scattered, indistinct puncta.
Colour, whitish. Shell of the male rather more slender, and less flexuous.
Length, "5 mm.

In brackish estuaries and in the sea, but apparently seldom reaching beyond
the littoral and laminarian zones. The distribution is, in fact, almost exactly
that of C. pellucida, ranging from such fresh-water habitats as Whittlesea, on the
one hand, to depths of 30-40 fathoms on the other.

Distribution. — Christiania Fiord (Gr. O. Sars) ; Bergen, Lervig, and Drobak,
Norway (A. M. N.); Iceland ; Eivers Scheldt and Maas, Holland (Gr. S. B.).

Fossil. — Scotland ; Cardiff, South Wales.

Although the characters above given are undoubtedly sufficient to separate
well-marked examples very decidedly from any of the most nearly related species,
C. confusa, C. pellucida, and C. macallana, it must yet be admitted that there occur
many intermediate conditions, which it is by no means easy to assign without
misgiving to any one of these species. But a similar observation holds good in
numberless other cases, and is, in fact, only one of many points of evidence in
favour of community of descent, and of organic plasticity sufficient to adapt forms
to constantly varying conditions of existence. The characters on which we chiefly
rely to distinguish C. porcellanea from its near allies are — firstly, the nearly equal
tapering of both extremities when seen from above, that is dorsally ; secondly, the
more arched and flexuous outline as viewed laterally ; thirdly, the smooth por-
cellaneous shell-surface, with little trace of punctation ; and, lastly, that in the
females there is no transverse furrowing of the shell, in this respect resembling
C. macallana.

5. Cythere macallana, Brady and Robertson.

(Plate xiv., figs. 19-21.)

1869. Cythere macallana, Brady and Kobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 368,
pi. xix., figs. 5-9.

1874. Cythere macallana, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 144, pi. xiii.,
figs. 1, 2.

Shell of the female, as seen from the side, subreniform, greatest height in
front of the middle, and equal to half the length ; anterior extremity evenly,
posterior obliquely, rounded ; dorsal margin rather boldly arched, ventral sinuated
in the middle. Seen from above, ovate, widest in the middle, rounded behind,
subacuminate in front ; width less than the height. Shell of the male longer and
narrower, as seen laterally more tapering towards the posterior extremity ;

of the North Atlantic and North -Western Europe.

129

dorsal margin almost straight. Seen from above, the sides are sub-parallel, and
the posterior extremity obtuse. Length, °4 mm.

This species has been dredged in Dublin, Westport, Birturbuy and Clifden
Bays, Ireland, and off the Scilly Islands ; and found in sands from the Yorkshire
River Ouse, the Humber, and Fowey Harbour (G. S. B. and D. E.). Dredged in
5 fathoms off Fairlie, Firth of Clyde, and in Clew Bay, Mayo (A. M. N.) ; Belfast
Lough and Irish Channel (Malcomson).

Distribution. — Naples (A. M. N.).

Fossil. — Kilchattan and Cumbrae, Scotland.

6. Cythere tenera, Brady.

1868. Cythere tenera, Brady, Mon. rec. Brit. Ostrac, p. 399, pi. xxviii., figs. 29-32.
1874. Cythere tenera, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 145, pi. xiii., figs.
6, 7.

1880. Cythere tenera, Brady, Report " Challenger," Ostracoda, p. 63, pi. xii., fig. 3 a-f.
1885. Cythere tenera, Cams, Prod. Faunas Medit., p. 295.

This species is easily distinguished from the four preceding not only by its
contour, but by its characteristic surface-markings, and the absence of transverse
furrowing.

Except that it is less common in fresh and brackish water, its distribution
follows exactly the lines of C. pellucida and C. porcellanea. The most characteristic
specimens occur in purely marine situations, but numerically they are not so
common as the two above-mentioned species. From fresh-water, our only recorded
locality is Whittlesea Dyke (G. S. B. and D. R.). Between tide-marks it seems to
be of rare occurrence, our only records of such habitats being Whitley and Culler-
coats, Northumberland (G. S. B.).

Distribution. — Oster Fiord, near Bergen, 100 fath. ; Hardanger Fiord, off
Lervig and Drobak, Norway ; Fosse de Cap Breton, Bay of Biscay, 30—200 fath.
(A. M. N.); Vigo Bay, "Challenger" Expedition (G. S. B.); Messina
(Seguenza) ; Besika Bay ; Hellespont ; Rivers Scheldt and Maas, Holland
(G. S. B.).

Fossil. — Scotland, Cardiff.

S 2

130 Brady and Nokman — Monograph of the Marine and Freshwater Ostracoda

7. Cythere mamillata, Brady.
(Plate xx., figs. 32, 33.)

I860. Cythere mamillata, Brady (New or imperfectly known species of Ostracoda), Trans. Zool. Soc,
vol. v., p. 373, pi. lix., figs. 6a-c.

Shell oblong, subreniform, deepest in front, twice as long as high ; anterior
margin well rounded, produced downwards below the level of the ventral margin ;
posterior extremity narrow, bent in the middle at an obtuse angle ; dorsal margin
arched ; ventral straight. Seen from above, oval. Surface of the valves minutely
punctate, and raised into several irregularly placed, rounded elevations, or mamillae.
Length, *32 mm.

Habitat. — Atlantic Ocean, 110 fathoms (G. S. B.).

8. Cythere (?) semipunctata, Brady.

1868. Cythere (?) semijmnctata , Brady, Mon. rec. Brit. Ostrac, p. 411, pi. xxix., figs. 33-38.
1874. Cythere (?) semipunctata, Brady, Crosskey, and Robertson, Mon. Post-tert Entom., p. 172; pi.
xvi., fig. 11-12.

This is a species of which the animal is still unknown, and the shell presenting
some unusual characters, its position in this genus remains doubtful.

Cythere semipunctata is widely distributed, but always scarce where found.

Additional localities. — Budle Bay and Seaton Sluice, Northumberland ; off coasts
of Durham and North Yorkshire ; River Ouse, Norfolk ; off the Eddystone
Lighthouse ; Ilfracombe ; Scilly Isles ; Westport Bay and Mulroy Lough, Ireland
(G. S. B. and D. R.); off Tarbert, Loch Fyne; between the Cumbraes, Firth of
Clyde, in 25 fath. (A. M. N.); Irish Channel and Belfast Lough (Malcomson).

Distribution. — Lervig Bay, Norway ; Fosse de Cap Breton, Bay of Biscay,
30-200 fath. (A. M. N.).

9. Cythere badia, Norman.
(Plate xv., figs. 3, 4.)

1868. Cythere badia, Brady, Mon. rec. Brit. Ostrac, p. 399, pi. xxix., figs. 29-32.

The figures and descriptions of this species given in the " Monograph" are
correct, and apply to the species originally described by Dr. Norman ; but the

of the North Atlantic and North-Western Europe.

131

synonym cicatricosa is referable to a closely-allied form, C. crispata, which was
supposed to be identical with C. badia. Several of the habitats there assigned to
C. badia belong properly to C. crispata. The following list shows completely the
present state of our knowledge as to the distribution of C. badia : —

Fowe}7 Harbour and Dungeness Bay (G. S. B.); Karnes Bay, in the Isle of
Cumbrae, and Westport Bay, Ireland; Scilly Isles (G. S. B. and D. R.); Rock
pools, at Mounts Bay, Cornwall ; Herm ; Guernsey ; Arran and Lough Carron,
N. B. ; Roundstone Bay, Ireland (A. M. N.) ; Belfast Lough and Irish Sea
(Malcomson).

Distribution. — Mediterranean, Syra, Smyrna, Constantinople (G. S. B.).

10. Cy there crispata, Brady.
(Plate xv., figs. 1, 2.)

1865. Cythere cicatricosa, G 0. Sars, Oversigt af Norges marine Ostracoder, p. 33 [not Reuss).
1868. Cythere badia, Brady, Les Fonds de la Mer., vol. i., p. 89.

1868. Cythere crispata, Brady, Ann. and Mag. Nat. Hist., ser rv., vol. ii., p. 221, pi. xiv., figs. 14, 15.

1869. Cythere cicatricosa, Brady and Kobertson, Ann. and Mag. Nat. Hist., ser. rv., vol. iii., p. 369,

pi. xix., figs. 13, 14.

1869. Cythere badia (in part), Brady, Mon. rec. Brit. Ostrac, p. 399 (not figures).

1874. Cythere crispata, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 146, pi. xii.,

figs. 52, 53 ; and pi. xiii., figs. 12, 13.
1880. Cythere crispata, Report " Challenger," Ostracoda, p. 72, pi. xiv., figs. 8 a-d.
1883. Cythere crispata, Seguenza, II Quaternario di Bizzolo, II., Gli Ostracodi, p. 30.
1885. Cythere crispata, Cams, Prod. Faunas Medit., p. 295.

Carapace of the female, as seen from the side, subrenif orm, higher in front than
behind, greatest height in front of the middle, and equal to more than half the
length ; anterior extremity rounded, and often slightly crenulated below the
middle ; posterior truncated and slightly rounded at the angles ; superior margin
gently arched, sloping from before backwards, its posterior angle somewhat
produced ; inferior margin slightly sinuated in the middle. Seen from above,
the outline is compressed, almost clavate, tapering, and narrowly rounded in
front, truncated behind ; lateral margins deeply emarginated near the posterior
extremity ; width considerably less than half the length. Surface of the shell
marked with irregularly sinuous depressions, and often with well-marked inter-
vening ridges. Colour, yellowish-brown ; the raised ornament often of a deeper tint
of blue or black. Shell of the male longer, narrower, and more flexuous in outline.
Length, "42 mm.

As already observed, this species was, in the " Monograph " confounded with
C. badia, which, however, has only an irregular surface ornament, without

132 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

the conspicuous sinuations and rugai which mark C. crispata ; the dorsal aspect
of the former is regularly ovate, while that of the present species is distinctly
truncate behind, and has well-marked lateral notches.

The specific name cicatricosa, applied by G. O. Sars to this species, having
been pre-occupied by Reuss and Bosquet for a form closely allied to, if not identi-
cal with, Baird's C. convexa, we adopt the name crispata already proposed by one
of us for a Mediterranean form which we believe to be only a more strongly
marked variety of this species, differing chiefly in size, and in the prominence of
the sculptured shell-markings. This southern form approaches very closely
C. canaliculata of Reuss, which, however, according to the figures given by that
author, is even more sharply sculptured. A specimen, referred to C. canaliculata,
was figured in the " Transactions of the Zoological Society" (vol. v., 1866, p. 373,
pi. lix., figs. 4 a— d), and others more completely in the Report on the Ostracoda,
of the " Challenger " Expedition (p. 73, pi. xiv., figs. 7a— d). The British C. cris-
pata, smaller and less pronounced in character than those from more southern
seas, may fairly be looked upon as depauperized examples of a species finding
more favourable conditions in warmer latitudes. The species ranges from Norway,
Britain, and the Mediterranean, to Australia and Hong-Kong.

C. crispata appears to occur all round the British coasts from low-water mark
downwards.

Distribution. — Christiania Fiord, Norway (G. 0. Sars) ; Mediterranean, Tenedos,
Besika Bay, and Hellespont (G. S. B.); Messina (Seguenza); Port Jackson, Aus-
tralia; Booby Island; Hong-Kong Harbour, " Challenger" (G. S. B.).

Fossil. — Scotland, Ireland, Norway, Sicily.

This species is usually an inhabitant of the Laminarian Zone ; while C. badia
affects tide-marks.

11. Cy there cribrosa, Brady, Crosskey, and Robertson.
(Plate xvi., figs. 17, 18.)

1874. Cythere cribrosa, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 146, pi. x., figs.
5-7.

1878. (?) Cythere cribrosa, Brady, Ostracoda, Antwerp Crag, Trans. Zool. Soc, p. 384, pi. lxiv., figs.
4«-6.

1886. Cythere cribrosa, Malcornson, Recent Ostracoda of Belfast Lough (Proc. Belfast Naturalists' Field
Club), p. 260.

Shell compressed, oblong ; seen laterally, rather higher in front than behind ;
greatest height equal to half the length ; anterior extremity evenly, posterior

of the North Atlantic and North -Western Europe.

133

obliquely rounded, and obsoletely angular about the middle ; superior margin
gently arched, highest in front of the middle, and terminating behind in an obtuse
angle ; inferior almost straight. Seen from above, compressed, ovate ; anterior
extremity sub-acuminate, posterior narrowly rounded, width less than the height.
End view sub-circular. Surface of the valves covered with rather closely reticu-
lated furrows which assume a concentric arrangement towards the margins.
Length, -55 mm.

A very pretty and distinct species, its nearest relative being perhaps C. robertsoni,
from which it differs chiefly in the character of its surface-marking, in its somewhat
greater size and less angular form.

As we do not possess a recent specimen we are obliged to describe and figure
the species from fossil examples.

The late Dr. Malcomson found a single specimen of this form at Rockport,
Co. Down, in 4 fathoms.

Fossil. — Bridlington, Yorkshire ; (?) Belgium (Antwerp).

12. Cy there teres, Brady.
(Plate xiv., figs. 36, 37.)
1869. Cythere teres, Brady, Les Fonds de la Mer., vol. i., p. 147, pi. xiv., figs. 17, 18.

Shell, seen from the side, elongated, subreniform, height nearly the same
throughout, and scarcely equal to half the length ; anterior extremity evenly,
posterior obliquely rounded ; dorsal margin almost straight, ventral very slightly
sinuatedin the middle. Seen from above, the outline is elongated, ovate, narrowed,
and obtusely pointed in front ; broad, and subtruncate behind, where there is a
median triangular prominence. The surface of the valves is smooth and glistening,
of a pale straw-colour, mottled with pellucid patches. Length, '5 mm.

Dredged in Dartmouth Harbour, 3-5 fath. (A. M. N.) ; Bay of Biscay (G. S. B.).

13. Cythere sulcifera, Brady.
(Plate xix., figs. 22, 23.)

1886. Cythere sulcifera, Brady, Les Fonds de la Mer, vol. iv., p. 197, pi. xv., figs. 3, 4.

Shell, viewed laterally, ovate ; greatest height central, and equal to half the
length ; anterior extremity very wide, evenly and regularly rounded, the margin
above sweeping evenly and regularly, without the slightest sign of angularity until

134 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

it reaches the highest portion of the valves, which is in their centre ; posterior
margin very much narrower than the anterior, subtruncate, with an angularity
at the junction with the dorsal slope; in some specimens (? males) the angularity
is greater, and takes the form of a pouting lip ; the lower portion edged with
a row of small tubercular teeth ; dorsal margin well arched, forming a continuous
sweep, the anterior portion of the arch declines much less suddenly than the
posterior, as in the latter case it has to meet the narrower termination ; ventral
margin straight. Seen from above, much compressed, narrowly elliptic ; greatest
tumidity posterior, attenuated evenly at the narrow extremities. Surface of valves
perfectly smooth on the front half, hinder portion sculptured with longitudinal
waved riblets and furrows, which sometimes, especially towards the dorsal margins,
are crossed by more slender riblets; but the marked character consists in the
former. Length, *9 mm.

Habitat. — "Porcupine" Exped., 1869. Stat. 19, east of Donegal Bay, in
lat. 54° 53' N., long. 10° 56' W., 1360 fath. ; and Stat. 42, lat. 49° 12' N., long.
12° 52' W., 862 fath. (A. M. N.).

14. Cythere corpulenta, n. sp.

(Plate xvi., figs. 11, 12.)

Shell ovate, very compressed in front, much swollen behind, especially towards
the ventral margin, over which it swells in a corpulent manner ; greatest height
nearly central, more than equal to half the length ; anterior extremity broad,
remarkably, broadly, and evenly rounded, the anterior third of the shell having a
semicircular outline ; posterior extremity much narrower, obtusely rounded or
subtruncate, with a rounded angularity at its junction with the dorsal margin ;
dorsal margin arched, the anterior slope very slight, the posterior greater, but
regular ; ventral margin straight, but overhung by the convex outline of the
obesity of the valves. Seen from above, somewhat narrowly heart-shaped; greatest
width near the hinder extremity, where the sides rapidly but arcuately converge,
while the extremity itself is slightly exserted ; towards the front the attenuation is
gradual and even, the extremity narrow. Valves very flat in front, and also at the
extreme posterior portion; in the middle and behind the middle very obese ; greatest
tumidity close to, and overhanging the ventral margin ; surface of valves finely
punctate, and sculptured with a few longitudinal thread-like riblets. Length,
•60 mm.

Cythere corpulenta is, perhaps, more nearly allied to C. sulcifera than to any other
species described in this Memoir, and has much the aspect of a Loxoconcha.

of the North Atlantic and North -Western Europe.

135

Habitat. — This species has only been found in Oster Fiord, a narrow and very-
deep inlet, about 15 (?) miles north of Bergen, Norway. It was there met within
four different dredgings, in depths ranging from 100 to 375 fathoms, but in each
case only a single example occurred (A. M. N.).

15. Cythere lamellifera, n. sp.

Shell, seen from the side, cuneiform ; greatest height anterior, somewhat less
than half the length ; anterior extremity remarkable on account of its broad and
even roundness ; the point of greatest protrusion is central, and the arcuation both
above and below this is bold, even, and regular ; the dorsal margin at about two-fifths
of its length from the anterior extremity slopes gradually backwards until near the
hinder end, where a sudden declivity forms an obliquely truncate posterior extre-
mity, the point of greatest protrusion of which is inferior ; ventral margin with a
small but deep sinus near the posterior extremity. The greatest tumidity is over
this sinus, behind which there is a sudden depression of the valve, while forwards
the compression is gradual, until the anterior portion of the valve is at once
much outspread and compressed. Round the anterior margin runs a smooth fillet,
and at a short distance within this a second narrow fillet ; the space between is
grooved, the groove being traversed by a few faint, transverse, thread-like lines ;
general surface of valves sculptured with several longitudinal, little-elevated,
lamelliform, slender, smooth, ribs ; posterior margin set round with obtuse
tubercles ; similar tubercles, but of much smaller size, are also to be seen round
the anterior edge. Length, about '4 mm.

A single valve dredged by H. M. S. " Valorous," in 1875. Stat. 16, lat.
55° 10' N., long. 25° 55 W., in 1785 fath. (A. M. N.).

It is not satisfactory to describe a species from a single valve ; but this seems
very distinct from all known forms, and from the extreme depth at which it was
found we cannot expect that many examples should be discovered.

We are unable to give an illustration, as the valve was unfortunately broken in
the process of examination.

In form this species approaches nearest perhaps to C. dorsoserrata, Brady,
described in the "Challenger" Report, from specimens taken near Tristan
d'Acunha.

•fKA>.*S ROY. DUB. SOC, N.S. VOL. IV. PABT II.

T

136 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

16. Cythere amissa, n. sp.

Shell subovate or nearly semicircular, the semicircle broken by a projected
process at the posterior extremity ; greatest height nearly central, and more than
half the length ; anterior margin having its greatest prominence near the junction
with the ventral, thence sweeping with a long regular curve to the highest point
of the shell, which is nearly central ; posterior margin subtruncate above, below
protruded into a rostrate process (such as is common in the genus Cytherura) ;
dorsal margin arcuate throughout, without any angularity before or behind ; hinder
declination more sudden than that in front ; ventral margin slightly convex.
Surface of valves sculptured all over with deep pits, which are mostly quadran-
gular, separated from each other by sharply-cut boundary walls ; the edges of the
valves are on all sides a little turned up, and form a narrow but distinct bordering-
line. Seen from above, diamond-shaped, but with the terminal angles blunt, and
the lateral rounded off ; ends equal. Length, about *75 mm.

Habitat. — Fosse de Cap Breton, Bay of Biscay, 30-60 fath. ; a single specimen
(A. M. N.).

Unfortunately, just as the description was written, and while measuring the
shell, it was let fall on the carpet, and all attempts to find it were in vain. We
are thus unable to give a figure. C. amissa is very distinct from all described
Cytheres known to us. The nearest thing to it is Cythere convoluta, Brady (Ann.
Nat. Hist., ser. iv., vol. ii. , p. 182, pi. xxi., figs. 3, 4), a species from the Mauritius.
From that species C. amissa differs in not having the retusion at the infero-posteal
angle ; not any angularity at the junction of the dorsal and hinder margins, the
dorsal margin sweeping right down to the rostrate process. Seen from above, the
ends are much narrower, and the sides not sinuated ; the surface of the valves
have not the flange beyond the encircling riblet, while the sculptured cells are
smaller and more numerous.

17. Cythere gibbosa, Brady and Robertson.

(Plate xiv., figs. 30, 31).

1869. Cythere gibbosa, Brady and Robertson, Ann. and Mag. Nat. Hist., Ser. iv., vol. m., p. 368, pi. xxi.,
figs. 1-3.

1874. Cythere gibbosa, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 150, pi. xvi., figs.
16-18.

Shell of female tumid ; seen from the side oblong, subtriangular or sub-
trapezoidal, highest in front of the middle; height equal to at least half the

of the North Atlantic and North -Western Europe.

137

length ; anterior extremity obliquely, posterior evenly rounded, the latter the
narrower ; dorsal margin prominent in front of the middle, thence sloping steeply
to the front, but more gently and almost in a right line backwards; ventral
almost straight. Seen from above the outline is ovate ; widest near the middle,
the width being considerably less than the height ; extremities acuminate. End
view broadly ovate. Shell of the male narrower and longer. Valves rather thin,
fragile, smooth and polished, bearing a few scattered hairs, which are papillose
at the base ; ventral surface longitudinally depressed in the middle. Length,
•4 mm.

Found in a large tidal pond at Westport Quay, Co. Mayo, amongst Zostcra ;
Eoundstone ; Mulroy Lough ; Canal at Belfast ; Karnes Bay, Isle of Cumbrae ; Isle
of Skye ; Greenock ; Loch Gilp ; and Montrose. Budle Bay, and several estuarine
situations on the Northumberland Coast and Thames Estuary (G. S. B. and D. R.).
Mouth of the Tweed ; Seaton-Carew Marshes, Co. Durham ; and Newport, Co.
Mayo (A. M. N.). Five miles S. S. E. of Maidens Lighthouse, Irish Channel, in
60 fathoms; Rockport, Co. Down (Malcomson).

Distribution. — Cape Frazer, 50—80 fath., Capt. Feilden's dredgings (G. S. B.).

This species is for the most part a denizen of brackish waters. The foregoing
list of localities, with the exception of Karnes Bay, the Irish Channel, and Cape
Frazer, presents us with such habitats ; for Mulroy Lough and Roundstone Bay,
though inlets of the sea, are both of them subject to a large influx of fresh water,
and at low tide must be only feebly saline. Budle Bay, on the other hand, is a
large, muddy expanse, covered by the sea at high water, while at low water a
small stream finds its way through it to the sea.

18. Cythere rubicla, Brady.
(Plate xv., figs. 22, 23.)

1866. Cythere rubida, Brady, Mon. rec. Brit. Ostrac, p. 400, pi. xxxii., figs. 71-74.

1869. Cythere drammensis, G. O. Sars, Undersogelser over Christianiafjordens Dybvandsfauna, p. 56.

The only locality given in the Monograph was Clachland Point, Arran, N. B.
(A. M. N.). It has since been found in Karnes Bay, Isle of Cumbrae (D. R.),
and Rockport, Co. Down (Malcomson). It is a very rare form, though stated
by Prof. G. O. Sars to be of frequent occurrence in Drammen Bay, on the
Christiania Fiord, where he took it in company with lacustrine species.

T 2

138 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

19. Cythere oblonga, Brady.

1866. Cythere oblonga, Brady, Mori. rec. Brit. Ostrac, p. 400, pi. xxxi., figs. 14-17.
1885. Cythere oblonga, Cams, Prod. Fauns Mediterranese, p. 297.

Originally described from a sponge-sand specimen ; again in the " Monograph "
from specimens found in shell-sand at the Mumbles ; more recently we have
dredged it among the Scilly Islands (G. S. B. and D. R); Salcombe, Devon, and
Plymouth (A. M. N.).

Distribution. — Drobak, Norway, in 30—120 fath. ; Fosse de Cap Breton, Bay of
Biscay, 25-60 fath. (A. M. N.); St. Malo ; Messina, and other parts of the
Mediterranean (G. S. B.).

Fossil. — Sicily (Seguenza).

20. Cythere albomaculata, Baird.
Synonym : C. alba, Baird, junior.

1865. Cythere albomaculata, Brady, Mon. rec. Brit. Ostrac, p. 402, pi. xxviii., figs. 33-39 ; pi. xxxix.,
figs. 3a-k.

1874. Cythere albomaculata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entorn., Scotland, p. 149,
pi. ix., figs. 1-4.

1884. Cythere albomaculata, Seguenza, II Quaternario di Rizzolo II. Gli Ostracodi, p. 26.

1885. Cythere albomaculata, Carus, Prod. Faunse Mediterranese, p. 296.

C. albomaculata is a sub-boreal type, rare on the Norwegian coast ; absent, so far
as we know, from the Arctic Ocean, but found abundantly all round the British
coasts in the littoral and laminarian zones ; and running to a considerable distance
up tidal rivers. It seems, however, to be absent from the Broads of Norfolk and
Suffolk (G. S. B. and D. R), though G. S. B. has found it in a freshwater lake at
Bolam, Northumberland. Sj)ecimens taken between tide-marks and amongst algse
are generally beautifully maculated, but those from sandy and muddy bottoms
are destitute of colour.

Distribution. — Lervig, Stordoen, Norway (A. M. N.). Iceland, Eastern Medi-
terranean and Constantinople ; Cape Verd ; Bay of Biscay and Vigo ; Fosse de
Cap Breton, 25 faths. (G. S. B.).

Fossil. — Scotland; Portrush, Ireland; Sicily.

of the North Atlantic and North -Western Europe.

139

21. Cythere leioderma, Norman.
(Plate xv., figs. 12, 13.)

1869. Cythere leioderma, Norman, Brit. Assoc. Report, 1868, p. 291.

1870. Cythere leioderma, Brady, Ann. Mag. Nat. Hist., ser. iv., vol. vi., p. 451, pi. xix., figs. 11-13.
1874. Cythere leioderma, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 149, pi. ix., figs. 5, 6.
1883. Cythere leioderma, Seguenza, II Quaternario di Rizzolo II. Gli Ostracodi, p. 27.

Shell, seen from the side, oblong, subquadrangular, rather higher in front than
behind ; greatest height equal to a little more than half the length ; anterior
extremity somewhat obliquely rounded, posterior truncated and slightly produced
below the middle ; dorsal margin highest in front, where it is obscurely angulated,
thence sloping gently, and almost in a straight line backwards ; ventral margin
very slightly sinuated in the middle. Seen from above, the outline is sub-ellipti-
cal, nearly twice as long as broad, slightly widest behind the middle ; extremities
very broadly rounded and nearly equal. Shell surface smooth, marked with a
few scattered, short, and rigid setse, which in some lights look deceptively like
small circular f papillae. Hinge margins depressed, processes very strongly
developed but not crenulated. Colour, yellowish or milky-white. Length, 1 mm.

Habitat— Unst Haaf, Shetland (A. M. N.).

Distribution. — Solems Fiord, Norway, 50—60 fathoms, a single specimen
(A. M. N.). Abundant, in a living state, in the Gulf of St. Lawrence; Iceland;
Cape Frazer, 80 faths. ; and Dobbs Bay, 46 faths., 79° 35' N., Captain Feilden's
dredgings (Gr. S. B.).

Fossil. — A single valve has been recorded from the Post-tertiary Strata, at
Bridlington, Yorkshire; and Prof. Seguenza has met with a single valve at
Rizzolo, in Sicily.

22. Cythere robertsoni, Brady.
(Plate xiv., figs. 32, 33.)

1868. Cythere robertsoni, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ii., p. 33, pi. iv., figs. 5, 8-10.
1874. Cythere robertsoni, Brady, Crosskey, and Robertson, Post.-tert. Entom., p. 221.

Shell of the female compressed. Seen from the sides, subcuneiform, much
higher in front than behind, greatest height situated in front and equal to rather
more than half the length ; anterior extremity broad and well-rounded, posterior

140 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

narrow and obliquely rounded ; superior margin nearly straight, sloping steeply
from the front backwards ; inferior sinuated in the middle, curved upwards
behind. Seen from above, compressed, oblong, with nearly parallel sides ;
anterior extremity sharply pointed, posterior suddenly tapered and obtuse, width
much less than the height. End view ovate, widest in the middle. Shell of the
male much narrower. Surface covered with closely-set, angular depressions.
Colour, yellowish. Length, -48 mm.

A small, but very distinct and pretty species, described first from specimens
dredged by Mr. D. Robertson, at Drobak, Christiania Fiord, in a depth of 30-35
fathoms.

We have no record of this pretty and well-marked species from any part of
the Scottish coast north of Loch Fyne. In Ireland we have found it in Dublin
and Westport Bays, and Dr. Malcomson dredged it in Belfast Lough and the
Irish Channel. Round the English coast it occurs generally, ranging from tide-
marks into all depths of water, always, however, rather sparingly.

Distribution. — Drobak, Norway (D. R.). Again in the last locality in 10-120
fathoms ; and in Stoksund, which is near the mouth of the Hardanger Fiord,
Norway, in 126 fathoms (A. M. N.).

Fossil. — Scotland, Loch Gilp ; Norway.

23. Cy there convexa, Baird.
Synonym. — C. punctata, R. Jones.

1868. Cythere convexa, Brady, Mon. rec. Brit. Ostrac, p. 401, pi. xxix., figs. 19-27 ; pi. xxxix.,
fig. 4.

1874. Cythere convexa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 150, pi. iii., figs.
14-17.

1884. Cythere convexa, Seguenza, II Quaternario di Rizzolo II. Gli Ostracoda, p. 20.

1885. Cythere convexa, Cams, Prod. Faunae Medit., p. 295.

Cypridina cicatricosa of Reuss was given in the Monograph with a (?) as a
synonym of this species. It has been regarded by the authors of the " Monograph
of Post-tertiary Entomostraca " as a distinct species, of which Cythere cicatricosa,
Bosquet, and Cythere arborescens, Brady, are given as synonyms.

Cythere convexa is met with pretty abundantly all round the British coasts from
low-water mark downwards. It is rare on the coast of Norway, but is common
further southwards, as far as the Bay of Biscay and the Mediterranean.

Distribution. — Lervig, Stordoen, Norway, a single specimen ; Fosse de Cap

of the North Atlantic and North -Western Europe.

141

Breton, Bay of Biscay, 25-60 fathoms; Naples (A. M. N.); Vigo, St. Malo ;
Hellespont, Beyrout, Jaffa, Latakie" (G. S. B.) ; Messina (Seguenza).
Fossil. — Scotland, Ireland, Sicily, Calabria (Seguenza).

24. Cy there speyeri, G. S. Brady.
(Plate xvii., figs. 16, 17.)

1868. Cythere speyeri, Brady, Ann. Mag. Nat. Hist. ser. iv., vol. ii., p. 222, pi. xv., figs. 8-11.
1868. Cythere speyeri, Brady, Les Fonds de la Mer., vol. i., p. 99, pi. xii., figs. 8-10.
1880. Cythere speyeri, Brady, " Challenger " Report, p. 79, pi. xx., figs. 2 a-p.

Shell of the female excessively tumid. Seen from the side, broadly ovate,
with a prominent posterior beak ; greatest height in the middle, and equal to two-
thirds the length ; anterior extremity fully rounded, and forming a continuous
curve with the dorsal margin, which is boldly arched ; posterior extremity pro-
duced below the middle into a prominent angular beak ; ventral margin
moderately convex. Seen from above, the outline is broadly ovate, not
twice as long as broad, widest behind the middle, lateral margins extremely
convex, converging gently towards the front and more abruptly backwards ;
anterior extremity subacuminate, posterior obtuse. End view broad, ovate,
widest below the middle, pointed at the apex, sides very convex. Left valve
larger than the right. Surface of the shell marked throughout with large
circular inpressed puncta ; hinge tubercles conspicuous ; no very marked en-
circling fillet. Length, -9 mm.

Distribution. — Bay of Biscay, Marquis de Folin; Tenedos, Colon, New Provi-
dence, St. Vincent, Cape Verd ; and by the "Challenger" Expedition at the
last-named locality, in 1070 to 1150 faths. (Stat. 93), and off Ascension Island
(Stat. 344), 420 fath. (G. S. B.); off Capri, Bay of Naples, 40 fath. (A. M. N.).

This species may be distinguished from C. convexa by its excessive tumidity.
Fine living specimens have the anterior margin and the posterior rostrate process
beset with minute spinules, and on the ventral margin, at the posterior extremity,
is a small spine. The posterior tubercles and spine are shown in the figure given
in the " Annals," and this figure most characteristically represents the species.

142

Beady and Norman-

' — Monograph of the Marine and Freshwater Ostracoda

25. Cythere marginata, Norman.

1868. Cythere marginata, Brady, Mon. rec. Brit. Ostrac, p. 413, pi. xxxi., figs. 5-8.
1868. Cythere laticarina, Brady, Mon. rec. Brit. Ostrac, p. 412, pi. xxxi., figs. 1-4.
1874. Cythere laticarina, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 158, pi. ix., figs.
23-26.

The type of C. marginata was an aged and worn specimen, which, since we
have had opportunities of studying larger series of forms, we find to be the same
as the more recently described C. laticarina.

Additional localities. — Scilly Islands, Birturbuy Bay (G. S. B. and D. R.) ; off
Tarbert, Loch Fyne, 25 fathoms ; Salcombe, Devon (A. M. N.) ; four miles east
of Gobbins, Irish Channel, in 60 fathoms (Malcomson).

Distribution. — Fosse de Cap Breton, 100 fathoms; Spitzbergen (G. S. B.) ;
Lervig Bay, Hardanger Fiord, Norway (A. M. N.).

Fossil. — Raised Beach, Oban, Scotland.

26. Cythere jeffreysii, Brady.

1868. Cythere jeffreysii, Brady, Mon. rec. Brit. Ostrac, p. 412, pi. xxix., figs. 51-55.
1874. Cythere jeffreysii, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 156, pi. iii., figs.
18, 19.

Additional locality. — Dredged off Penarth Head, South Wales (G. S. B. and
D. R.).

Fossil. — Raised Beach, Oban, Scotland.

27. Cythere limicola, Norman.
Synonyms. — C. nodosa, G. 0. Sars ; C. areolata, Brady.

1868. Cythere limicola, Brady, Mon. rec. Brit. Ostrac, p. 405, pi. xxxi., figs. 38-41 [at »o»,figs. 43-46).
1874. Cythere limicola, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 154, pi. x.,
figs. 1-4.

1878. Cythere limicola, Brady, Ostracoda, Antwerp Crag, Trans. Zool. Soc, vol. x., p. 389, pi. lxiv.,
figs. 9 a-b,

This is certainly one of the least common of the British Cytheres.
Additional localities. — The Minch ; in 25 fathoms in the channel between the
greater and lesser Islands of Cumbrae, in the Firth of Clyde (A. M. N.); one

of the North Atlantic and North -Western Europe.

143

mile off the Gobbins, in the Irish Channel, 15-18 fathoms; Belfast Lough, 6—10
fathoms (Malcomson). This species seems to be more abundant and finer in
growth on the north-east coast of England than in any other locality.

Distribution. — Norway; very rare, Lofoten Islands, and " sinus Nidaroensis,"
6-10 fathoms (G. 0. Sars) ; Baffin's Bay (G. S. B.).

Fossil. — Scotland, Canada.

28. Cythere cuneiformis, Brady.
Synonym : Cythere ventricosa, G. 0. Sars.

1868. Cythere cuneiformis, Brady, Mon. rec. Brit. Ostrac, p. 404, pi. xxxi., figs. 47-54.

1874. Cythere cuneiformis, Brady, Crosskey, and Eobertson, Post-tert. Entorn., p. 154, pi. x., figs. 23-26.

This is a widely and generally distributed species, on the British coasts,
though found always very sparingly. For the most part it inhabits depths of
15-40 fathoms ; but it occurs in several shallow estuarine localities in Northumber-
land, and has once been found between tide-marks on mud-covered rocks at
Whitley, Northumberland (G. S. B.).

Distribution. — Lervig, Stordoen, Norway (A. M. N.); Drobak and Langesund,
Norway (G. O. Sars).

Fossil. — Scotland, Norway.

29. Cythere navicula, Norman.
(Plate xvi., figs. 15, 16.)

1868. Cytherura navicula, Norman, Last Beport Dredging among the Shetland Isles, Brit. Assoc. Report,
p. 292.

1870. Cythere fidicula, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. rv., vol. vi., p. 21, pi. viii.,
figs. 8-11.

Shell, as seen from the side, trapezoidal ; height equal to not much more than
one-third of the length ; extremities narrowly rounded below, about their middle
sloping at both extremities obliquely upwards to join the short and straight dorsal
margin, which they join at an obtuse angle; ventral margin almost straight, but
slightly protruded in front of the middle as a rounded tubercular prominence.
Behind the middle there is sometimes another pair of similar tubercular processes, but
these are smaller and less pronounced. Seen from above, elongated, subhexagonal,
with parallel sides, and obtuse or subtruncated extremities ; the two anterior angles
well-marked, the posterior rounded off ; width equal to the height. Seen from below,

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. U

144 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

the ventral surface exhibits at its anterior angles two prominent rounded emi-
nences, behind which it becomes slightly constricted, again swelling out into a
convex margin behind the middle (where there is sometimes another pair of
rounded eminences). End view subtriangular, apex rounded off, basal angles
prominent and sharp, sides convex, base slightly concave. Shell marked with
irregular and sinuous longitudinal raised lines, which on the concave ventral
surface are especially conspicuous. Length, "65 mm.

This is a very remarkable species. Dr. Norman placed it in Cytherura, but we
are now agreed that its nearest ally is perhaps Cythere cuneiformis, of which
Professor Gr. 0. Sars has examined the animal, and found it to be a Cythere.

Dr. Brady, in his original description, was struck by the contour of the shell,
as seen from below, as being " remarkably fiddle-shaped," and from this circum-
stance chose his specific name. On the other hand, it presented to Dr. Norman's
imagination another figure, and he wrote 11 Ventral aspect, boat-shaped, the
resemblance most striking ; centrally depressed at the juncture of the valves ;
bows moderately sharp, of good breadth of beam, sculptured with raised,
thread-like concentric lines, representing the timbers, while the small nodulous
processes stand for the thole-pins. The dorsal and end views bear out the
allusion, the former representing a boat viewed from below, with a well-marked
keel, and the latter being triangular, with gently-rounded sides." Hence he
adopted the specific name, " navicular

This species has now been found in many localities, but is remarkably rare
numerically, one or two specimens at each place being all that have been met
with.

Papa, Shetland ; Budle Bay, Northumberland ; estuary of Thames ; Round-
stone, Ireland; inside St. Mary's, Scilly (G. S. B. and D. R.) ; St. Magnus' Bay,
Shetland, 30—60 fathoms ; the Minch ; Salcombe, Devon ; Birturbuy Bay, Ireland
(A. M. N.).

Distribution. — Estuaries of the Scheldt and Meuse, Holland (G. S. B.); off
Sartoro, in Bergen Fiord, Norway, 15 fathoms, one specimen (A. M. N.).

30. Cythere globulifera, Brady.

1868. Cythere globidijera, Brady, Mori. rec. Brit. Ostrac, p. 406, pi. xxxi., fig. 42.
1874. Cythere globulifera, Brady, Crosskey, and Eobertsou, Mon. Post-tert. Entom., p. 155, pi. ix., figs.
18-20, and (?) 21, 22 ; pi. xii., figs. 11, 12 ; plate xv., figs. 19, 20.

This appears to be an extremely rare form in a recent state.
Additional locality. — Two miles S.S.E. of Maidens Lighthouse, Irish Channel,
in 62 fathoms (Malcomson).

of the North Atlantic and North -Western Europe.

145

Distribution. — Stoksund, near the mouth of the Hardanger Fiord, Norway, in
126 fathoms (A. M. N.) ; Spitzbergen, Cape Frazer, 50-80 fath., Capt. Feilden's
dredgings (G. S. B.).

Fossil. — Scotland, England (Bridlington), Canada.

31. Cythere cluthce, Brady, Crosskey, and Robertson.

(Plate xiv., figs. 25-27, vol. xvii., figs. 35, 36.)

1874. Cythere cluthce, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom, p. 153 ; pi. xiii., figs.
16, 17.

1886. Cythere cluthce, Malcomson, Recent Ostracoda of Belfast Lough (Proc. Belfast Nat. Field Club),
p. 260.

Shell, as seen from the side, subquadrate ; highest in front ; greatest height
equal to more than half the length ; anterior extremity broad and well-rounded ;
posterior narrow and subtruncate, only slightly rounded ; superior margin almost
straight, sloping from before backwards ; inferior slightly sinuated in the middle.
Seen from above, the outline is oblong, subrectangular, with parallel irregularly
sinuous sides, tapered off towards the front, which is truncated ; posterior extremity
irregularly rounded. Shell-surface irregularly mamillated, closely set with small
subrotund pittings. The valves are encircled by a broad, swollen marginal lip, the
central portion being elevated and very uneven. Length, *35 mm.

The late Mr. Malcomson says of this species, that " although rare, it seems to
be generally distributed in the deeper water " of the Irish Sea and Belfast Lough.
He gives the following localities : — First, in the Irish Channel, 2—5 miles S.S.E. of
Maidens Lighthouse, 60—72 fathoms; half a mile off Coalpit Bay, 13 fathoms.
Secondly, in Belfast Lough, off White Head, 10—18 fathoms. We are indebted to
Mr. T. Scott for specimens dredged in about 20 fathoms in Loch Fyne. From one
of these specimens our descriptions and illustrations are drawn up.

Distribution. — Cape Frazer, 80 fath. in Capt. Feilden's dredgings, Nares'
Arctic Expedition (Gr. S. B.).

Fossil. — Scotland.

32. Cythere complexa, Gr. S. Brady.
(Plate xix., figs. 31, 32.)

1866. Cythere complexa, Brady, On Ostracoda dredged amongst the Hebrides (Brit. Assoc. Report),
p. 210.

1866. Cythere limicola (partim), Brady, Mon. Brit. Ostrac, p. 405, pi. xxxi., figs. 43-46.

Shell, seen laterally, rhomboidal, a little higher in front than behind ; height
equal to more than half the length ; anterior extremity obliquely truncated, rounded

U 2

146 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

off below and obscurely angulated above ; posterior very oblique, truncated, forming
a projecting beak above the middle, postero-dorsal angle broadly and obliquely
truncated, emarginate ; dorsal margin almost rectilinear, ventral gently convex.
Seen from above, the outline is subhexagonal, the margins very irregular, strongly
and sharply mucronate behind and very obtuse in front ; greatest width equal to
the height, and situated behind the middle ; lateral margins very deeply excavated
in the middle, converging sharply towards the front, and still more abruptly behind.
Surface of the valves irregularly waved and rugose, bordered in front by a broad
encircling flange, and near the posterior extremity sinking suddenly in a transvere
direction, thus forming with the ventral margin a rectangular ridge. Length,
•4 mm.

Originally described from specimens dredged by the late Dr. Jeffreys and
A. M. N. in the Minch. It has been more recently dredged by Dr. Norman in
a depth of 126 fathoms at Stoksund, Norway.

33. Cythere villosa (G. 0. Sars).

1868. Cythere villosa, Brady, Mon. rec. Brit. Ostrac, p. 411, pi. xxix., figs. 28-32.
1874. Cythere villosa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 157, pi. iii., figs.
7-13.

1888. Cythereis emaryinata , Dahl, Die Cytheriden der Westlich. Ostsee., p. 13, pi. i., figs. 13-26, 30.

One of the most abundant and most widely -distributed of the British marine
species, ranging for the most part from low water to about 40 fathoms. Many new
localities might be added to those given in the "Monograph." It is, in fact,
scarcely ever absent either from dredgings or from littoral shell sand.

Distribution. — In Norway it has been dredged in from 3—180 fathoms, Bergen ;
off Sartoro, near Bukken ; Lervig Bay, Stordoen; Stoksund (A. M. N.). Holland,
River Scheldt; Davis Strait, Lat. 67° 17' N., Long. 62° 2V W, six feet below
low-water mark (G. S. B. and D. R.), Iceland ; Bay of Biscay (Gr. S. B.).

Fossil. — England, Scotland, Ireland, Canada.

34. Cythere pulchelta, Brady.
(Plate xv., figs. 7, 8).
1868. Cytheve pulchella, Brady, Mon. rec. Brit. Ostrac, p. 404.

1868. Cythere pulchella, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ii., p. 32, pi. v., figs. 18-20.

1869. Cythere pulchella, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 369, pi. xx.,

figs. 1-3.

1874. Cythere pulchella, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 157, pi. iii., figs.
29-37.

Additional localities. — Firth of Forth, Stromness, and Loch Ryan (D. R.); Kil-
chattan Bay, Isle of Bate ; Karnes Bay, Isle of Cumbrae ; off Ilfracombe ; Birturbuy,

of the North Atlantic and North -Western Europe.

147

Clifden, and Westport Bays, Ireland (G. S. B. and D. R.) ; Filey Brig, Yorkshire ;
Dartmouth Harbour (A. M. N.); Irish Channel and Belfast Lough (Malcomson).

Distribution. — Holland, river Scheldt ; Davis Strait, Lat. 67° 17' N., Long.
62° 21' W., six feet below low-water mark (G. S. B. and D. R.).

Fossil. — Scotland, Ireland.

35. Cy there borealis, Brady.
(Plate xv., figs. 18, 19.)
1868. Cythere borealis, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ii., p. 31, pi. iv., figs. 1-4, 6, 7.

Shell of female, seen laterally, subreniform ; highest in front of the middle ;
greatest height equal to half the length ; anterior extremity very deep, obliquely
rounded ; posterior subtruncate, somewhat emarginate above the middle, below
this emargination the shell slopes obliquely forward without curvature to meet the
inferior margin ; dorsal margin gradually declining with a gentle sweep backwards
from the highest point of the shell in front of the middle ; ventral margin incurved
centrally, and pouting in front. Outline, as seen from above, long-ovate, widest in
the middle ; extremities equal, obtuse ; width about equal to half the length. The
right valve differs from the left in shape, being higher with the dorsal margin more
boldly arched, distinctly excavated in front, and much more conspicuously emar-
ginate behind. The hinge groove in the united valves, as seen from above, is very
wide and deep ; the hinge joint is formed, in the left valve, by acrenulated median
bar, with a moderately strong anterior tooth, in the left valve by an anterior tooth
and a slightly crenulated posterior projection. The shell of the male is longer and
narrower, with the anterior margin produced downwards, and numerously ser-
rated. Surface of the valves covered with shallow, rounded impressions, but not
at all rugose or tuberculated. Colour, yellowish-brown, or purplish. Antennules
robust, six-jointed, fourth and fifth joints coalescent; last four armed with strong,
flexuous, apical spines, flagellum of antennae in the female short and robust.
Feet long and strong ; second joint of last foot shorter than the two succeeding
joints, terminal claws long and pectinated on the concave border. Male copulative
organs of moderate size ; posterior segment obtusely triangular. Length, 1 mm.

This species is nearly related to C. emarginata (G. O. Sars), but is altogether
destitute of the peculiar angulated ridge which runs across the hinder portion of
the valves in that species ; the surface markings are also less sharply cut, and less
angular. It is still more closely related to C. villosa, and indeed looks very like a
strongly developed and much larger form of that species ; but while the general
outline of the shell is very like that of the two species to which we have referred,

148 Brady and Norman — Monograph of the Marine and Freshwater Ostracorla

the extension or oblique backward slope at the infero-posteal corner is peculiarly-
characteristic of the present species.

The young are still deeper in proportion in front than the adult, and the surface-
sculpture at that age more resembles punctation.

The only British Station in which this species has been found is at Seaton-
Carew, in the County of Durham, on mud-covered rocks, near low-water mark
(G. S. B.).

Distribution. — Davis' Strait, lat. 67° 17' N., long. 62° 21' W. (Dr. Sutherland);
Holstenbourg Harbour, 10 fathoms; Godhaven, 5-25 fathoms; lat. 69° 31' N.,
long. 56° 1' W., muddy bottom, 100 fathoms, "Valorous" Exped. (A. M. N.).
Dobbs' Bay, 79° 35' N., 46 fathoms, Captain Feilden's dredgings in Nares' Arctic
Expedition (G. S. B.).

The types of C. borealis were those found in Davis' Strait by Dr. Sutherland,
as above mentioned ; they occurred six feet below low- water mark. From one of
these specimens our illustrations are drawn.

36. Cy there fuscata, Brady.
(Plate xv., figs. 9-11.)

1868. Cy there fuscata, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 47, pi. vii., figs. 5-8.

Length of female, "60 mm. ; of male, '7b mm. Shell of the male, seen
laterally oblong, subreniform ; rather higher in front than behind ; height
equal to half the length ; anterior extremity boldly rounded, posterior slightly
emarginate above the middle ; superior margin almost straight, inferior rather
deeply sinuated in the middle. Seen from above the outline is oblong-ovate, with
nearly parallel sides, and nearly twice as long as broad ; acutely pointed in front,
broadly rounded or subtruncate behind. Surface of the valves closely and finely
punctate ; colour, yellowish-brown. The shell of the female is much smaller, and
higher in proportion to the length.

This is a very distinctly-marked species, and so far as we at present know, is
confined to estuarine and brackish or sub-brackish situations in Holland and the
East of England. The British Stations in which we have found it are as follow : —
Horsey Mere ; Hickling, Ormesby and Oulton Broads ; Breydon Water ; Rivers
Ouse (Norfolk), Bure, Deben, Thames (G. S. B. and D. R.).

Distribution. — Holland, Rivers Scheldt and Maas, Mr. Davison (G. S. B.
and D. R.).

of the North Atlantic and North -Western Europe.

149

37. Cy there macchesneyi, Brady and Crosskey.
(Plate xvii., figs. 30, 31.)
1871. Cythere macchesneyi, Brady and Crosskey, Geological Magazine, vol. viii., p. 4, pi. ii., figs. 1, 2.

Shell, seen from the side, compressed, subreniform ; greatest height in front, and
equal to half the length ; the anterior extremity evenly rounded, posterior nar-
rower and obliquely rounded ; dorsal margin straight, sloping from before back-
wards, and slightly angular at each end ; ventral margin deeply sinuated in the
middle. Seen from above, ovate, widest in the middle, width rather less than the
height ; sides subparallel, converging abruptly towards the front, which is bluntly
pointed, rounded off behind. Surface thickly set with small circular impressions
arranged somewhat concentrically ; ventral surface furrowed. Length, '5 mm.

Distribution. — Shore sand, the Berg Beach, lat. 82° 29' N., Captain Feilden's
dredgings in N ares' Arctic Expedition (Gr. S. B.).

Fossil. — Post-tertiary deposits, Montreal and Saco, North America.

38. Cythere septentrionalis, Brady.
(Plate xvi., figs. 13, 14.)

1866. Cythere septentrionalis, New and imperfectly-known Marine Ostracoda, Trans. Zool. Soc, vol. v.,
p. 375, pi. lx., figs. 4 a-f.

Shell oblong, subquadrilateral, very tumid ; height equal to half the length,
or, in male, less ; anterior margin broad and obliquely rounded ; posterior
narrower, subtruncate ; dorsal margin nearly straight, with a slight convexity in
the middle, and sloping gently backwards to the posterior hinge ; ventral margin
slightly sinuated in front of the middle. Seen from above ovate, very tumid,
width equal to height, extremities very obtusely rounded. End view nearly
round, the breadth exceeding the height. Ventral aspect flattened, wide, longi-
tudinally grooved. Valves sculptured with angular cells, which gradually coalesce
towards the margin, forming there larger spaces, which take the form, on the
ventral surface, of sharply-cut, longitudinal furrows. The reticulated sculpture
prevails on the central parts of the dorsal and lateral aspects ; but over the whole
ventral surface longitudinal grooving only is visible. Length, 1*4 mm.

Distribution — A remarkably fine species, of which many specimens were found
in Dr. P. C. Sutherland's dredgings at Hunde Islands, Baffin's Bay, in 60-70 fath.
(Gr. S. B.).

150 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

39. Cy there echinata (G. 0. Sars).
(Plate xvi., figs. 9, 10.)

1865. Cythereis echinata, G. 0. Sars, Oversigt of Norges Ostracoder, p. 44.

1866. Cythere catenate/,, Brady, New and imperfectly known Marine Ostracoda, Trans. Zool. Soc, vol.

v., p. 374, pi. lx., figs. 2 ar-d.
1880. Cythere irpe.v, Brady, Beport " Challenger " Ostracoda, p. 107, pi. xvii., figs. 2 a-d.
1886. Cythere monacantha, Brady, Les Fonds de la Mer, vol. iv., p. 197, pi. xv., figs. 5, 6.

Shell, seen from the side, subovate, or inclining to subquadrangular, short and
high ; remarkable for the position and character of the greatest tumidity, which
consists of a gradual swelling-up of the shell (without any augularity or ex-
crescesces) to a point situated a little within the ventral margin on the posterior
half of the shell ; height equal to nearly two-thirds of the length ; anterior
extremity higher than posterior, very widely and evenly rounded, the margin
flattened, and crenulated or spined ; posterior extremity subtruncate, and slightly
emarginate above, the margin flattened, and crenulated or spined, two spines
on the infero-posteal corner (if perfect) are larger than any others on the shell ;
dorsal margin, at first, very prominent, and angled, then slightly concave, and lastly
convex; ventral margin showing very slight trace of sinuation. Seen from above,
ovate; greatest breadth situated a little behind the middle and equalling the
height ; margins evenly arched, the anterior extremity much more drawn out than
the hinder. Surface of valves covered with very numerous slender spines, which
when the shell is perf ect appear to be arranged in regular concentric lines, although
in worn specimens the sculpture of the surface is found to be reticulated ; the
spines along the dorsal margin, two or three at the infero-posteal corner, and one
or two at the higher portion of the greatest tumidity are generally larger than the
rest. Length, 1 mm. to 1'25 mm.

Sars describes the animal : — " No eyes. Colour, pale brownish-yellow. All the
limbs elongated and slender, yellow. Upper antennae distinctly six- jointed, last
joint long and slender, about equal to the combined length of the two preceding,
ending in three spiniform setae ; lower antennae slender, with greatly elongated
terminal nails ; flagellum very short. Mandibular palp having the last two joints
very elongated, the last extremely narrow and curved ; branchial appendage fur-
nished with five setae, the outer two of which are rudimentary. Feet very slender,
last pair having the second joints about equal in length to the two following. Basal
portion of the copulatory organ of the male sub triangular, the extremity elongated-
ovate, and bent inwards.'"

of the North Atlantic and North-Western Europe.

151

Distribution. — In Norway rare in 30-100 fathoms Christiania Fiord, extending
northwards to the Lofoten Islands, where it is found in 300 fathoms (G. O. Sars):
Drobak, 30—100 fathoms ; Hardanger Fiord, off Midso Lighthouse, 210 fathoms ;
Bergen Fiord, south of Bukken, 150-200 fathoms; Oster Fiord, 375 fathoms:
"Porcupine," 1869, Stat. 19, lat. 54° 53' N.,long. 10° 56' W., 1360 fathoms; Stat.
41, lat. 49° 4' N., long. 12° 22' W., 582 fathoms : " Valorous » Exped., 1875, Stat.
12, lat. 56° 11' N., long. 37° 41' W., 1450 fathoms (A. M. N.). "Challenger"
Exped., Stat. 73, lat. 38° 30' N., long 31° 14' W., 1000 fathoms; Stat. 78, lat.
37° 34' N., long. 25° 13' W., 1000 fathoms; Stat. 335, lat. 32° 24' S., long.
13° 5' W., 1425 fathoms (G. S. B.).

The types of Dr. Brady's C. catena/a were found in M 'Andrew and Barrett's
Norwegian dredgings, and they unquestionably represent the young of this species.

40. Cythere acanthoderma, Brady.

1866. Cythere scabra, Brady, New and imperfectly-known Marine Ostracoda, Trans. Zool. Soc, vol. v.,

p. 380, pi. lxi., figs. 8 a-d {non Minister).
1880. Cythere acanthoderma, Brady, Beport " Challenger " Ostracoda, p. 104, pi. xviii., figs. 5 n-e.
1885. Cythere acanthoderma, Cams Prod. Faunas Medit., p. 300.

Shell oblong, subovate, tumid, the greatest tumidity on the posterior half of the
shell a little within the ventral margin; in the adult covered everywhere with more
or less strongly developed, very irregular, blunt and rugged spines. Seen from the
side the valves are subovate or somewhat pear-shaped, highest near the front, the
height being equal to nearly two-thirds the length ; anterior extremity well and
broadly rounded ; posterior narrower and also rounded, being most produced in the
middle ; dorsal margin sloping backwards evenly from the front hinge, its margin
very much laciniated into spiny processes ; ventral margin slightly convex. Seen
from above, the outline is subovate, not twice as long as broad, widest near the
middle ; sides curved, converging gradually towards the front, but abruptly behind ;
extremities wide and truncated. The end view is subtriangular, equilateral, with
convex sides and rounded angles. The margins of the shell, from whatever aspect
it is viewed, are excessively rugged, and the spines with which it is everywhere
thickly beset, have a tendency to enlarge and become bifurcate or trifurcate at their
apices, a very remarkable character which enables it at once to be distinguished
from many allied forms, as for example, from C. dasyderma in which the
spines are invariably simple. There are certain spines in the present species which
usually assume a greater development than the rest, namely, one or two over the
hinge, and especially one at the distant termination of the dorsal margin, and one

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II.

X

152 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

at the hinder termination of a ridge which runs along the most tumid portion of the
shell, a little way within the ventral margin.* Length 1 to 1 "25 mm.

Young specimens have the shell in a great measure smooth, the first spines
developed being those which surround the margin, and those which crown the ridge
passing along the most tumid portion of the shell ; the bifurcation of the spines will
be found to be a helpful character in the determination of these early stages.

Distribution.—1' Porcupine " Exped., 1869, Stat. 19, lat. 50° 53' N., long.
10° 56' W., 1360 fathoms; "Valorous" Exped., 1875, Stat. 12, lat. 56° 11' N.,
long. 37°41'[N., 1450 fathoms; Stat. 16, lat. 55° 10' N., long. 25° 58', 1785
fathoms (A. M. N.). One of the "Challenger" Stations comes within the area to
which this paper specially applies, Stat. 64., lat. 30° 35' N., long. 50° 27' W., 2750
fathoms; it was met with in six other " Challenger" Stations, in depths ranging
from 580 to 2050 fathoms, midway between the Cape of Good Hope and Kerguelen
Island, to the north of Australia, and in both North and South Pacific (G. S. B.),
Messina, Sicily (Seguenza), Abrolhos ; Crete, 360 fathoms, Cap. Spratt(G. S. B.).

Fossil. — Sicily (Seguenza).

41. Cy there dictyon, Brady.

1880. Cythere dictyon, Brady, Eeport " Challenger," Ostracoda, p. 90, pi. xxiv., figs. 1 a-y.

Shell of the female, seen from the side, oblong, quadrangular, not much higher
in front than behind, height equal to more than half the length ; anterior extremity
well rounded, fringed below the middle with numerous short teeth ; posterior sub-
truncated, scarcely rounded, irregularly toothed on the lower half; the dorsal margin
sloping gently from before backwards, and always, in adult specimens, more or
less irregularly jagged, while in some cases the indentations are remarkably deep ;
ventral margin more or less convex. Seen from above the outline is lozenge-shaped
or somewhat hastate, about twice as long as broad, sides subparallel or converging
gently towards the front, extremities broad and truncated. End view triangular,
with convex margins and rounded angles. Shell-surface covered with an irregular
network of ribs, the main lines of which have often an obscurely radiate arrange-
ment, originating in an obsolete central tubercle ; just within and parallel with the
ventral margin is a prominent, sharply-cut ridge, which is often produced beyond
the middle of the valve into a strong spine, but is continued in a less prominent
style round the anterior and posterior portions of the shell, thus enclosing an

In old and ragged examples, such as those figured in the "Challenger" Report, the spines
and ridge, to which attention is here called, lose their prominence, owing to the great development of
all the other spiny processes.

of the North Atlantic and North- Western Europe.

153

elevated central area. The shell of the male has usually a more strongly-developed
spinous armature than is seen in the female. Length 1 '0 mm.

Distribution. — Cythere dictyon is almost ubiquitous in the greatest depths of the
ocean, and was found by Dr. Brady, in sands from no less than twenty-four stations,
extending over the North and South Atlantic, the Indian and Pacific Oceans. The
shallowest water in which it has been known is Humboldt Bay, Papua, in 37
fathoms. In fifteen stations it was found in depths which exceeded 1000 fathoms,
and three of these were below 2000 fathoms.

Six "Challenger" Stations were within the range of the present Paper, that is, in
the North Atlantic, north of latitude 35° N. They were as follows : — Stat. 64,
lat. 35° 35' N., long. 50° 27' W., 2790 fathoms ; Stat. 70, lat. 38° 25' N., long.
35° 50' W., 1675 fathoms ; Stat. 73, lat. 38° 30' N., long. 31° 14' W., 1000 fathoms;
Stat. 75, lat. 38° 37' N., long. 28° 30' W., 450 fathoms ; Stat. 76, lat. 37° 34' N.,
long, 25c 13' W., 1000 fathoms; Stat. 78, lat. 37° 24' N., long. 25° 13' W., 1000
fathoms. These dredgings constitute a line commencing about half-way between
the Bermuda Islands and the Azores, and extending thence to the latter islands
(G. S. B.).

This, and C. dasyderma and C. acanthoderma, have an enormous geographical
range, apparently ranging throughout the world in the great ocean abysses.

42. Cythere dasyderma, Brady.

1880. Cythere dasyderma, Brady, Eeport " Challenger " Ostracoda, p. 105, pi. xvii., figs. 4 a-f ; pi. xviii.,
figs. 4 a-f.

1885. (Jytkere dasyderma, Cams. Prod. Faunae Mediterranese, p. 300.

Shell tumid ; seen from the side oblong, subovate or subquadrangular ;
greatest height situated near the front, and equal to about two-thirds of the length ;
anterior extremity boldly rounded ; posterior narrower, rounded or subtruncate ;
dorsal margin sloping gently backwards from the front, which is elevated over the
hinge joint ; ventral margin slightly convex ; the entire circumference broken into
closely-set, but short and blunt teeth. Seen from above the outline is ovate, widest
near the middle, about twice as long as broad, lateral margins gently and evenly
curved, extremities broad, and nearly equal, obtusely rounded or truncated. End
view broadly ovate, rounded off above, and centrally emarginate below. Surface
of valves with closely -packed rather small angular excavations, from the intervals
between which arise numberless (usually short and blunt) spines, the shell in every
aspect presenting a rough appearance. Length -65 to '9 mm. In some specimens the
spines are arranged in three or four rows anteriorly, and within the ventral margin in

X 2

154 Brady and Norman — Monograph of the Marine and Frcshivater Ostracoda

two distinct lines, in other examples the arrangement in these parts as elsewhere
is confused.

Distribution.— 11 Porcupine " Exped., 1869 Stat., 19, lat. 54° 53' N., long.
10° 56' W., 1360 fathoms: "Valorous" Exped., 1875, Stat. 12, lat. 56° 11' N.,
long. 37° 41' N., 1450 fathoms; Stat. 13, lat. 56° 1' N., long. 34° 42' N., 690 fathoms
(A. M. N.). In the "Challenger" Exped. C//there dasyderma was found in no
less than twenty dredgings from the North and South Atlantic, North and
South Australia, New Zealand, and North and South Pacific (almost to Cape Horn).
The only station in the district to which this Paper has special reference was
Stat. 70, lat. 38° 25' N., long. 35° 50' W., 1675 fathoms. The least depth in which
it has been found was at Stat. 167, lat. 39° 32' S., long. 171° 48' E., 150 fathoms.
The following are the greatest depths :— Stat. 5, lat. 24° 20' N., long. 24° 28' N.,
2740 fathoms ; Stat. 246, lat. 36° 10' N., long. 178° 0' E., 2050 fathoms ; Stat. 332,
lat. 37° 29' S., long. 27° 31' W., 2200 fathoms; Stat. 346, lat. 2° 42' S., long.
14° 41' W., 2350 fathoms (Gr. S. B.). Seguenza has found it in the Mediterranean
at Messina.

Fossil. — Sicily (Seguenza).

43. Cythera scabrocuneata, Brady.

(Plate xv., figs. 28, 29.)

1880. Cythere scabrocuneata , Brady, Report "Challenger" Ostracoda, p. 103, pi. xvii., figs. 5 a-/; pi.
xxiii., figs. 2 a-c,

1880. Cythere dorsoserrata, Brady, ibid., p. 102, pi. xxiii., figs. la-d.

Shell of the female, seen from the side, in shape as a long triangle, with the
apex behind, greatest height in front, less than or equal to half the length,
anterior extremity broad, well rounded ; posterior much narrower, and produced
slightly below the middle to a conspicuous point ; dorsal margin generally gibbose
over the hinge, thence gradually sloping backwards ; ventral margin arcuate in
front, slightly sinuated about the middle, and behind this, gently curved and
converging equally with the dorsal towards the posterior extremity ; a flattened
fillet borders the ventral and more markedly the anterior and posterior margins,
and this, together with the dorsal margin, is more or less toothed or jagged. Seen
from above the outline is ovate, twice as long as broad, in front broadly rounded,
behind somewhat hastate. Surface of valves thickly covered with nodulous
elevations, which when perfect terminate in short, blunt, spiny points ; on the
other hand, when the nodules are themselves rubbed away, the surface is found to
be reticulated, being sculptured with round or hexagonal cells. Length, "77 mm.

of the North Atlantic and North -Western Europe.

155

Distribution.— "Porcupine" Exped., 1869, Stat. 19, lat. 54° 53' N., long. 10° 56'
W., 1360 fathoms ; " Valorous " Exped., 1875, Stat. 12, lat. 59° 11' N., long. 37° 41'
W., 1450 fathoms (A. M. N.). Cotes des Landes, Bay of Biscay, Marquis de Folin
(G. S. B.). Dredged in the "Challenger" Expedition, Stat. 162, off East
Moncoeur Island, Bass' Straits, in 38-40 fathoms ; Stat. 233 b, in Inland Sea,
Japan, lat. 34° 20' N., long. 133° 35' E., 15 fathoms, and Wellington Harbour,
New Zealand.

44. Cythere trispicata, n. sp.

(Plate xvi., figs. 5, 6.)

Shell, seen from the side, narrowly oblong, greatest height posterior, equal to
about two-fifths of the length ; dorsal and ventral margins nearly straight and
subparallel, very slightly converging forwards from the highest point, which is
near the posterior extremity ; anterior margin narrow, obliquely truncated ;
posterior margin broad, obliquely truncate, sharply angulated both above and
below. Seen from above, the extremities are greatly compressed, while the
central portion swells out to give support to the three long spikes — presently to be
described — which are projected divergently like the prongs of a trident. Surface
of valves furnished with numerous blunt tuberculations, the most conspicuous of
which pass in series round the margins of the valves at both extremities ;
central portion of valves swollen and supporting three very remarkable spike-like
projections ; the anterior of these is the longest, and is directed forwards, its height
being equal to about half the length of the shell ; the central is of similar shape
but shorter, while the posterior, which is a little behind the middle, is much
thicker, transversely flattened, and shorter than the others. Length about "5 mm.

This is a most remarkable form, totally different to all species, recent or fossil,
known to us. The nearest approach to it is perhaps to be found in Cythere
umbonata, Williamson, as figured by Marsson (" Die Cirripedien und Ostracoden
der weissen Schreibkreide der Insel Riigen," pi. m., fig. 15), rather than the
figures of earlier authors ; the outline is of similar type, and there is one spike
near the extremity of the valves.

The single specimen here described has been kindly sent to us for description
by the Marquis de Folin, who found it on the coast of Les Landes, south-west of
France.

156 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

45. Cythcre latiniarginata, Speyer.
(Plate xv., figs. 16, 17.)

1863. Cythcre laUmargmata, Speyer, Die Ostrac, der Casseler Tertiarbild, p. 22, pi. iii., figs. Sa-il.
1865. Cythereis abyssicola, G. 0. Sars, Oversigt af Norges Ostracoder, p. 43.

1868. Cythere abyssicola, Norman, Last Report Dredging among Shetland Isles (Brit. Assoc. Report),
p. 290.

1874. Cythcre abyssicola, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 163, pi. xvi., fig. 6.
1878. Cythere abyssicola, Brady, Ostracoda Antwerp Crag, Trans. Zool. Soc, vol. x., p. 389, pi. lxiv.,
figs. 8a-d.)

Shell of female, seen laterally, oblong, subquadrate, greatest height situated in
front and equal to more than half the length ; anterior extremity broadly and
obliquely rounded, and bordered with a series of minute teeth, which are continued
round the ventral angle ; posterior much narrower, obliquely truncated, and
emarginate in the middle, and often having four or five small teeth towards the
inferior angle; dorsal margin sinuated in the middle, and much elevated in a
gibbose fashion over the anterior hinge ; ventral straight, with a slight median sinua-
tion. Seen from above, the outline is irregular, twice as long as broad, the lateral
margins nearly parallel, each showing two protuberances separated from each
other by an intervening hollow, extremities prominent and truncated. Valves hard
and thick, distinctly areolated, and surrounded, except on the dorsal margin, by a
broad, thickened band, which forms a keel-like flange, and in front is divided by
a narrow furrow into two. In the middle of each valve is a prominent rounded
tubercle. The shell of the male is narrower and more angular, but the adults of
both sexes seem to be about equal in length. Colour, pale, yellowish -brown.
Length, -7 mm.

Sars thus describes this animal: — "Eyes very small, rounded. Antennae
moderately elongated, third and fourth joints of the upper pair united, the last
short; third joint of lower antennae narrower than usual, terminal nails elongated.
Branchial appendage of the mandibular palp very small, bearing only two setae,
one of which is rudimentary and hamate. Feet slender, second joint of last pair
subequal in length to the two succeeding joints combined, terminal nail very
slender. Copulatory organs of the male small, the extremity obtusely triangular."

Habitat— Unfit Haaf, Shetland, 20-25 miles N.N.W. of Burrafirth, 100-140
fathoms (A. M. N.). A single specimen, apparently referable to this species, and
possibly fossil, was found among sand dredged by Mr. E. C. Davison in the
river Ouse, at Lynn (G. S. B.).

of the North Atlantic and North -Western Europe.

157

Distribution. — Drobak, 60-120 fathoms ; Lofoten Islands, down to 300 fathoms
(G. O. Sars); Oster Fiord, north of Bergen, 100—200 fathoms; south of Bukken,
Bergen Fiord, 150-200 fathoms ; Lervig Bay, 20 fathoms; Stoksund, Hardanger
Fiord, 126 fathoms; Christiania Fiord, 30-100 fathoms: "Porcupine" Exped.,
1869, Stations, 74, 75, 76, between lat. 61° and 62° N., and long. 1°, 44°, and 3°
44' W., in 267—640 fathoms ; " Valorous " Exped., Lievely Harbour, Disco, Green-
land, 5-20 fathoms; and Davis Strait, lat. 64° 5' N., long. 56° 47' W., 410 fath.
(A. M. N.) ; Spitzbergen (G. S. B.).

Fossil. — Scotland (Oban) ; Cassel; Belgium (Antwerp).

46. Gythere lepida, n. sp.
(Plate xv., figs. 20, 21.)

Shell elongated, oblong, narrower behind, tumidity gradually increasing
backwards to a little before the hinder extremity, where the convexity is
greatest on the ventral side, behind this the posterior extremity is suddenly
compressed ; greatest height on the anterior third, equal to two-fifths of the length ;
anterior extremity — which is the highest part of shell — very broadly and
evenly rounded, its point of greatest projection central ; dorsal margin nearly
straight, gradually and slightly declining backwards ; ventral margin pouting
in front, and slightly emarginate centrally. Viewed dorsally, cuneiform, greatest
breadth near the posterior extremity, the sides converging thence evenly for-
wards to a blunt extremity, behind the greatest breadth the valves are
abruptly and deeply constricted, and form a mucronate extremity, which is
broadly truncate terminally. Valves having a massive broadly-rounded fillet
(as in C. latimarginata) at both ends : all the rest of the surface is sculptured with
hexagonal cells. Length, *9 mm.

In some specimens short, blunt, tubercular nodules adorn the fillet, the
dorsal margin, and anterior part of the valves, and in these specimens the cells
are smaller, not hexagonal but very irregular, and varying in form.

In outline and fillet this species is allied to O. latimarginata, but is longer,
while the surface sculpture and aspect from above are wholly different.

Distribution.— North Atlantic, lat. 56° 1' N., long 34° 42', W., 690 fath.
Valorous" Exped., 1875 ; Stat. 13 (A. M. N.).

158 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

47. Cythcre hoptonensis, Brady, Crosskey, and Robertson.
(Plate xv., figs. 26, 27.)

1874. Cythere hoptonensis, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 168, pi. xiv.,
figs. 4-6.

Shell seen from the side quadrangular, higher in front than behind, greatest
height equal to more than half the length ; anterior extremity wide, well rounded,
and minutely crenulated, posterior much narrower and truncated, only slightly
rounded ; dorsal margin sloping in an irregularly sinuous line from before back-
wards, gibbose at the anterior hinge ; ventral margin nearly straight. Seen from
above lozenge-shaped, with very irregular convex sides and wide truncated
extremities, twice as long as broad. The valves are produced into a flattened
flange in front and behind, the surface very irregularly waved and ribbed and
having in the centre a large rounded tubercle. Length, "77 mm.

Dredged off Muros, Galicia, Marquis de Folin (G. S. B.).

48. Cythere crenidata (G. O. Sars).
(Plate xv., figs. 5, 6.)

1865. Cythereis crenidata, G. 0. Sars, Oversigt af Norges marine' Ostracoder ("Vid-Selsk. Forhand), p. 39.
1868. Cythere crenidata, Norman, Last Eeport Dredging among the Shetland Isles (Brit. Assoc. Rep.),
p. 291.

Shell very tumid, the width as great as the height, subquadrate, higher in
front than behind, greatest height equal to, or more than half the length ; anterior
extremity very wide, obliquely rounded, the margin crenulated with little points ;
posterior narrower, subtruncate, and slightly emarginate, greatly depressed below
the level of the rest of the shell, the infero-posteal corner much exserted, and
furnished with little blunt spinules ; dorsal margin flexuous, at first elevated
slightly and well rounded, then slightly concave before the middle, then nearly
straight, and ultimately declining suddenly to meet the truncate posterior
extremity (in the young the dorsal margin is straight) ; ventral straight, or very
slightly sinuated in front of the middle. Seen from above, very wide in the
middle, with nearly parallel though flexuous sides ; anteriorly narrowly truncate,
posteriorly jutting outwards into blunt angles, beyond which the valves are
suddenly contracted, and take the form of a beak-like truncated extremity.
Surface of valves indistinctly areolated, and finely punctate anteriorly, and the

of the North Atlantic and Nor tit -Western Europe.

159

lower portion of the posterior margin thickened, and forming a double lip, the
inner margin of which is crenulated, as has been already described ; lateral sur-
face uneven, a rounded knob in the middle of the valves, just in front of their
centre ; behind this two riblets pass backwards, one near the dorsal, and the other
near the ventral margin — the latter the more conspicuous — and terminate in two
projected knobs, beyond which the valves are suddenly depressed to form the
posterior extremity. Length, 75 mm.

Sars says of the animal : 11 Eyes very large, seen laterally elongate-elliptical,
seen from above semilunar. Colour, pale yellow-brown. Antennas as in C. emargi-
nata ; feet and their terminal claws more slender."

Habitat— Rate 20-25 miles N.N.W. of Burrafirth, Shetland, in 100-140
fathoms (A. M. N.).

Distribution. — Very rare in 6-10 fathoms near Langesund, West Norway (G. O.
Sars). Oster Fiord, north of Bergen, 100-200 fathoms ; off Sartoro, 15-40 fath.
and south side of Kors Fiord, 180 fath. ; Lervig Bay, Stordoen, 10—28 fath. ;
Stoksund, 80-126 fath., Norway: "Valorous" Expedition, 1875, Davis Strait,
lat. 64° 5' N., long. 56° 47' W., 410 fath., and Lievely Harbour, Disco, Greenland
(A. M. N.).

49. Cythere quadridentata, Baird.

1868. Cythere quadridentata, Brady, Mon. rec. Brit. Ostrac, p. 413, pi. xxxi., figs. 19-30.
1874. Cythere quadridentata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 161,
pi. xiii., fig. 22.

1885. Cythere quadridentata, Carus, Prod. Faunae Mediterranean, p. 299.

Additional localities. — Off North Coast of Scotland ; off Coasts of Durham and
North Yorkshire ; dredged in Birturbuy, Clifden, and Westport Bays, and Mulroy
Lough, Ireland (Gr. S. B. and D. R.J; Isle of Cumbrae; Plymouth; Killary
Bay, and deep water off Valentia, Ireland (A. M. N.).

Distribution. — Lervig Bay, Norway, 10—25 fath. (A. M. N.) ; Bay of Biscay ;
Crete, Captain Spratt (G. S. B.).

Fossil. — Scotland (Loch Gilp).

50. Cythere emaciata, Brady.

1868. Cythere emaciata, Brady, Mon. rec. Brit. Ostrac, p. 414, pi. xxx., figs. 31-37.

1874. Cythere emaciata, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 161, pi. ix., figs. 14-17.

1885. Cythere emaciata, Carus, Prod. Faunae Mediterranean, p. 299.

Additional localities. — At Lamlash, and off North Coast of Scotland; off Durham
and North Yorkshire ; in the Ouse at Lynn ; off Ilfracombe ; Eddystone, and

'[BANS. ROY. DUB. SOC, N.S. VOL. IV., PABT II. Y

160 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

among' the Scilly Islands. Dredged in Birturbuy, Clifden, and Westport Bays,
and Mulroy Lough, Ireland (G. S. B. and D. R.) ; Plymouth; Valentia Harbour,
Ireland (A. M. N.).

Distribution. — Messina (Seguenza) ; Naples (A. M. N.) ; Fosse de Cap Breton,
135 fathoms, Marquis de Folin (Gr. S. B.).

Fossil. — Scotland (Oban), Ireland (Portrush), Calabria, Sicily.

51. Cythere rnncinata, Baird.
(Plate xv., figs. 24, 25, 30, 31.)

1850. Cythere runcinata, Baird, On several new species of Entomostraca (Proc. Zool. Soc. Lond., part

xviii., Annulosa), p. 254, pi. xviii., figs. 7-9.
1850. (?) Cythere prava, idem, ibidem, pi. xvii, figs. 13-15.

1868. Cythere stimpsoni, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 48, pi. vii., figs. 9-12.
1880. Cythere stimpsoni, Brady, Eeport Ostracoda " Challenger " Exped., p. 85, pi. xxi., figs. 6 a-h.
1885. Cythere stimpsoni, Carus, Prod. Fauna? Mediterranean, p. 297.

(Not Cythere stimpsoni, Brady, Les Fonds de la Mer., vol. i., p. 78, pi. x., figs. 7-10. j

Male. Shell seen from the side elongated, subquadrangular, greatest height
situated near the front and equal to rather less than half the length ; anterior
extremity boldly rounded, fringed with a series of short, sharp teeth, which are
largest below the middle ; posterior extremity narrower, obliquely truncated above
the middle, and armed with four or five teeth below ; dorsal margin sloping from
before backwards, sinuated in front, and sharply emarginated at the posterior
extremity ; ventral slightly sinuated in the middle. Seen from above, the outline
is elongated and somewhat boat-shaped, nearly thrice as long as broad, and about
equal in width throughout ; sides nearly parallel, and converging abruptly towards
the extremities, which are truncated and formed by the greatly-thickened margins
of the valves. The shell-surface is coarsely reticulated, and the sides of the
valves are marked by three sharply-cut longitudinal ribs ; a similar curved rib
running just within the anterior margin and being continued for a short distance
along the ventral surface. The shell of the female differs in being shorter and
stouter, the height greater in proportion to the length. Length of the male, "98
mm. ; of the female, '87 mm.

This species is closely allied to Cythere emaciata, Brady, and though Dr. Baird's
types have not been preserved, or, at any rate, are not accessible, there seems
little reason to doubt that the specimens described and figured by him under the
specific names runcinata and prava, belong to the two sexes of a single species —
probably to the Mediterranean form, which we have been accustomed to call

of the North Atlantic and North -Western Europe.

161

C. stimpsoni, but which does not really belong to the species (an Oriental one)
originally described by Dr. Brady under that name. Dr. Baird's specimens were
from Tenedos, from which place we possess specimens, as well as from various
other localities in the Mediterranean.

Habitat. — Dredged in Dartmouth Harbour and Plymouth Sound (A. M. N.),
which are at present the only known British localities.

Distribution. — Vigo Bay, dredged by "Challenger" Expedition (G. S. B.);
Fosse de Cap Breton, 135 fathoms (G. S. B.), and some locality 30—200 fathoms
(A. M. N.); "Valorous" Expedition, Stat. 13, lat. 64° 5' N., long. 34° 42' W., 690
fathoms (A. M. N.). In the Mediterranean it occurs commonly, especially in the
Levant and Grecian Archipelago (G. S. B.).

52. Cythere tuberculata (G. 0. Sars).
(Synonym — C. mutabilis, Brady.)

18G5. Cythere clathrata, var. lyrata, and (?) var. latirnarginata, Brady, Trans. Zool. Soc, vol. v., p. 377,
pi. lix., figs. 12, 13.

1868. Cythere tuberculata, Brady, Mon. rec. Brit. Ostrac, p. 406, pi. xxx., figs. 25-41.

1874. Cythere tuberculata, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 164, pi. v., figs.
7-12.

1885. Cythere tuberculata, Carus, Prod. Faunae Mediterranae, p. 296.

Generally distributed round the British Islands, in depths of 4 to 40 fathoms ;
also in Northern Europe, and extending southwards to the Mediterranean.

Distribution. — Widely distributed in 6—40 fathoms, Norway (G.O. Sars). Lervig;
Bergen; and Drobak, Norway (A. M. N.); Holsteinborg Harbour, Greenland,
10 fath., and Lievely Harbour, 5-10 fath., "Valorous," 1875 (A. M. N.) ; Iceland;
Hammerfest Harbour ; Spitzbergen ; Gulf of St. Lawrence ; Hunde Islands, in
Baffin's Bay, 60-70 fath. off Bache Island, about lat. 78° N., Capt. Feilden in
Nares' Arctic Voyage ; West Indies (G. S. B.); Fosse de Cap Breton, Bay of Biscay,
180-200 fath. (A. M. N.); Messina, Sicily (Seguenza).

Fossil. — Scotland, England, Wales, Ireland.

53. Cythere bradii, De Folin.
(Plate xvi., figs. 3, 4.)

1869. Cythere bradii, De Folin, Les Fonds de la Mer, vol. i., p. 148, pi. xiv., figs. 21-24.

Shell tumid, viewed laterally subrhomboidal, higher in front than behind,
height much more than half the length ; anterior extremity widely arched ; dorsal

Y2

162 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

margin deeply excavated behind the eye, then convex, and behind suddenly
sloping; ventral margin gently flexuous. Seen from above, subhexagonal, the
extremities widely mucronate, and the sides very convex ; greatest breadth central,
subequal to the height. Surface of valves adorned with three very prominent
flexuous ribs. Length, *7 mm.

Habitat. — Bay of Biscay (Marquis de Folin).

54. Of/there concinna, Rupert Jones.
(Synonym. — Cythereis ctavata, G. 0. Sars.)

1865. Cythere concinna, Brady, Mon. rec. Brit. Entorn., p. 408, pi. xxvi., figs. 28-33 ; pi. xxxviii.,
fig. 7.

1874. Cythere concinna, Brady, Crosskey, and Kobertson, Mon. Post-tert. Entorn., p. 1G0, pi. iv., figs.
1-20.

Additional localities. — Dredged in Loch Long and Loch Fyne, off Rothesay, and
Roseneath, in the Firth of Clyde ; in the Firth of Forth, off coasts of Durham, and
North Yorkshire (Gr. S. B. and D. R.) ; Unst Haaf, and St. Magnus' Bay, Shetland,
50-60 fath. ; Portree Bay, Isle of Skye; off Valentia, Ireland (A. M. N.) ; Irish
Channel, 13-18 fath.; Belfast Lough, 4— 10 fath. ; Rockport and Brown's Bay, N.E.
Ireland ; tide-marks (Malcomson).

Distribution. — Cape Frazer, 80 fath., Nares' Arctic Exped., Captain Feilden ;
Spitzbergen; Iceland; Hammerfest Harbour (G. S.B.); Christiania Fiord, 6—20
fath., and Lofoten Islands, Norway (G. O. Sars) ; Drobak, 30-100 fath., and Stok-
sund, 126 fath., Norway (A.M.N.) ; Davis Strait, lat. 67° 17' N., long. 62° 21' W.,
six feet below low- water mark (G. S. B. and D. R. ).

Fossil. — England (Bridlington), Scotland, Ireland, Norway, and Canada.

55. Cythere dubia, Brady.
1868. Cythere dubia, Brady, Mon. rec. Brit. Ostrac, p. 409, pi. xxxii., figs. 75, 76.

The only specimens known were found in sand dredged from the Unst Haaf,
Shetland, in 1863, where it was dredged again, in 100 fath., in 1867 (A. M. N.).

of the North Atlantic and North-Western Europe.

163

56. Cythere emarginata (G. 0. Sars).
(Plate xvi., figs. 1, 2.)

1868. Cythere emarginata, Brady, Mori. rec. Brit. Ostrac, p. 166.

1874. Cythere emarginata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 166, pi. v., figs.
1-6.

The specimen described in the monograph was found by Mr. Robertson off
Shetland, where it has since been twice met with by Dr. Norman, on the Unst
Haaf and in St. Magnus' Bay.

Distribution. — Lofoten Islands, 6—12 fatli., and Oxfiord, Finmark (G.O. Sars) ;
Lervig Bay, Stordoen, 3—25 fath., and off Lervig, 50—100 fath. ; Stoksund,
80-100 fath. ; Haakelsund, Kors Fiord 3-10 fath., all in Norway (A. M. N.) ; Spitz-
bergen, Mr. Lamont (G. S. B.); Godhavn and Holstenbourg Harbour, 5—25 fath., and
Davis Strait, lat. 69° 31' N., long. 56° 1' W., 100 fath., "Valorous" Exped.
(A. M. N.); Hammerfest Harbour; Davis Strait, lat. 67° 17' N., long. 62° 21' W.
(G. S. B. andD. R.); Iceland (G. S. B.); Franklin Pierce Bay, 13 fath., Nares'
Arctic Expedition (Captain Feilden).

Fossil. — England, Scotland, Ireland, Norway, and Canada.

An Arctic species, which is more common as we proceed northwards, and
appears to have been abundant in the Glacial epoch.

57. Cythere finniarchica (G. O. Sars).

1868. Cythere finniarchica, Brady, Mon. rec. Brit. Ostrac, p. 410, pi. xxxi., figs. 9-13.
1874. Cythere finmarchica, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 153 ; pi. x., figs.
18-21.

Additional localities. — Dredged off North coast of Scotland ; off coasts of Durham
and North Yorkshire ; in the river Ouse, Norfolk ; off Ilfracombe, and the Eddy-
stone Lighthouse ; Fowey Harbour (G. S. B. and D. R.) ; Shetland ; the Minch ;
Herm, tide-marks (A. M. N.) ; Irish Channel and Belfast Lough (Malcomson).

Distribution. — Oxfiord, Finmark (G. O. Sars); Haakelsund in Kors Fiord, Norway,
3-10 fath. ; Holsteinborg Harbour, Greenland, 10 fath., and Davis Strait
(lat. 69° 31' N., long. 56° 1' W.), in 100 fath., " Valorous " Exped. (A.M.N.) ; Bay
of Biscay; St. Vincent, Cape Verd(G. S. B.).

Fossil. — Scotland, Norway.

164 Brady and Norman — Monograph of the Marino and Freshwater Ostracoda

58. Cy there costata, Brady.
(Plate xvi., figs. 7, 8.)

1866. Cythere costata, Brady, Trans. Zool. Soc, vol. v., p. 375, pi. lx., figs. 5 a-f.
1868. Cythere costata, Norman, Brit. Assoc. Beport, 1868, p. 290.

1874. Cythere costata, Brady, Crosskey, and Bobertson, Bost-tert. Entom., p. 166, pi. v., figs. 21-24.

Female. Carapace compressed, oblong, seen from the side subquadrangular,
highest in front of the middle, greatest height equal to somewhat more than half
the length ; anterior extremity broad and well-rounded ; posterior narrow,
obliquely truncated, slightly produced below the middle, inferior angle rounded
and divided into four or five short obtuse teeth ; dorsal margin sloping from the
front backwards in a somewhat sinuous line ; ventral straight or very slightly
sinuated. Seen from above, compressed, irregularly ovate, greatest width situated
behind the middle, and equal to rather more than one-third of the length, sides
irregularly sinuated and converging gradually to the extremities, which are equal
and obtusely pointed. The surface is pitted with closely-set large angular exca-
vations, and each valve has three or four obliquely transverse sharply-cut ribs, which
rise from a single longitudinal ridge just within the ventral border and is continued
round the anterior margin. Length, 1*1 mm. The shell of the male is longer,
narrower, and distinctly quadrangular ; its greatest height is less than half the
length, and the superior margin of the left valve is raised into a conspicuous
prominence over the anterior hinge.

Habitat. — Dredged on the Unst Haaf, Shetland (A. M. N.).

Distribution. — The type specimens were dredged by Dr. Sutherland in a depth
of 60-70 fath., off the Hunde Islands, Baffin's Bay (G. S. B.); Holsteinborg Har-
bour, Greenland, 10 fath., living, one $ and one $, " Valorous" Expedition
(A. M. N.) ; Gulf of St. Lawrence ; Franklin Pierce Bay, 13—15 fathoms, and Smith
Sound, 78° 37' N., Captain Feilden in Nares' Arctic Expedition (G. S. B.).

Fossil. — England (Bridlington and Hopton Cliff), Scotland (Paisley).

The species is very similar to C. emarginata, but differs in the surface ornament,
in the presence of the teeth, at the posterior margin, and in the general outline as
seen from above and below.

of the North Atlantic and North -Western Europe.

165

59. Cy there angulata (G. 0. Sars).

1865. Cythere clathrata, var. nuda, Brady, Trans. Zool. Soc, vol. v., p. 377, pi. lix., figs. 9, 10.
1868. Cythere angulata, Brady, Mon. rec. Brit. Ostrac, p. 409, pi. xxvi., figs. 39-42.
1874. Cythere angulata, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 162, pi. iv., figs. 21-24 ;
pi. x., fig. 22.

Additional localities. — Off the north coast of Scotland ; Stromness and Firth of
Forth ; Loch Ryan, and several places in the Firth of Clyde ; on the Northumber-
land, Durham, and Yorkshire coasts ; off Scarborough ; Dublin, Westport, Clifden,
and Birturbuy Bays, and Mulroy Lough, Ireland (G. S. B. and D. R.) ; off Tarbert,
Loch Fyne (A. M. N.) ; off the Maidens Lighthouse, Irish Channel, 60 fath. ;
Belfast Lough, 6—8 fath. ; between tide-marks, Rockport, Donaghadee, and other
places in N.E. Ireland (Malcomson).

Distribidion. — Christiania Fiord ; Oxfiord, Finmark (Gr. 0. Sars); Haakelsund,
Kors Fiord, 3— 10 fath. ; LervigBay, 3—25 fath; Lungegaards-vandet, Bergen ; Hol-
lingspollen near Drobak, 3-10 fath., Norway ; Holsteinborg Harbour, Greenland,
10 fath. ; Davis Strait, lat. 69° 31' N. long. 56° 1' W., 100 fath., "Valorous " Exped.
(A.M.N.) ; Iceland; Hammerfest Harbour; Davis' Strait, lat. 67° 17' N., long. 62°
21 W., six feet below low-water mark (G. S. B. and D. R.).

Fossil. — England (Bridlington), Scotland, Ireland (Portrush), Norway.

60. Cythere mucronata (G. O. Sars).

(Synonym. — C. spinosissima, Brady.)

1868. Cythere mucronata, Brady, Mon. rec. Brit. Ostrac, p. 415, pi. xxvi., figs. 34-34«.
1878. Cythere mucronata, Brady, Mon. rec. Brit. Ostrac. Antwerp Crag., Trans. Zool. Soc, vol. x., p. 395,
pi. lxvii., figs. 3 a-cl.

At the time of the publication of the monograph only a single valve of this
tine species had been found in sand dredged on the Unst Haaf, Shetland ;
two additional valves have since been procured from the same locality (A. M. N.).

Distribution. — Hammerfest Harbour (G. S. B.); Lofoten Islands, 300 fath.
(G. O. Sars) ; Stoksund, near the mouth of the Hardanger Fiord, Norway,
126 fath. (A. M.N.) The types of Brady's " C. spinosissima" were from
31' Andrew and Barrett's dredgings from Norway.

Fossil. — Belgium (Antwerp).

166 Brady and Norman — Monograph of the Murine and Freshwater Ostracoda

61. Cy there canadensis, Brady.

(Plate xv., figs. 14, 15.)
1870. Cythere canadensis, Brady, Aim. and Mag. Nat. Hist., ser. iv., vol. vi., p. 452 ; pi. xix., figs. 4-6.

Shell seen from the side, elongated quadrate, slightly higher in front than
behind ; height equal to about half the length ; anterior extremity obliquely
rounded, posterior rectangularly truncated and showing one or two minute
nodular projections ; dorsal margin gently sloping from the front, but prominent
over the anterior hinge ; ventral sinuated in the middle and curved upwards be-
hind. Seen from above, the outline is club-shaped, with subparallel sinuous sides,
but widest towards the posterior extremity ; extremities broad and unevenly trun-
cated ; posterior much the wider of the two. Shell-surface uneven, covered with
small rounded excavations, showing a slight transverse depression in the middle
and another behind, and bordered in front by a wide protuberant flange. Length,
•66 mm.

This species approaches very closely C. latimarginata, Speyer, but differs from it
in having a less developed marginal band and a less angular outline when viewed
from above. The forms referred to by Dr. Brady (loc. cit.) as showing a ridged
surface ornament belong certainly to other species.

Distribution. — The type specimens were found in dredgings made by Mr. G. M.
Dawson in the Gulf of St. Lawrence (G. S. B.) ; and a few examples have been
noticed in dredged material got by the " Valorous " in Davis Strait, lat. 66° 55'
N., long. 55° 30' W., 57 fathoms (A. M. N.)

62. Cythere dawsoni, Brady.
(Plate xvi., figs. 19, 20.)

1870. Cythere dawsoni, Brady, Recent Ostracoda of the Gulf of St. Lawrence, Ann. and Mag. Nat. Hist.,

ser. iv., vol. vi., p. 453, pi. xix., figs. 8-10.

1871. Cythere dawsoni, Brady and Crosskey, Fossil Ostracoda Post-tert of Canada and New England,

Geological Magazine, pi. ii., figs. 5-7.
1878. (?) Cythere dawsoni, Brady, Ostracoda Antwerp Crag, p. 393, pi. xlvi., figs. 3 a-b.

Shell viewed laterally quadrangular, highest in front, greatest height equal to
half the length ; anterior extremity obliquely rounded, bordered with strong blunt
teeth ; posterior narrower, rectangularly truncate, slightly rounded ; dorsal margin

of the North Atlantic and North -Western Europe.

167

nearly straight, gently sloping backwards, irregularly emarginate ; ventral almost
straight. Seen from above, subhexagonal ; sides nearly parallel, suddenly tapering
towards the extremities, which are obtusely mucronate ; outline throughout very
rugged. Surface of valves marked by irregularly rounded, scattered tubercles and
by two irregular longitudinal rows of transversely elongated tubercular eminences.
Length, "75 mm.

Distribution. — Gulf of St. Lawrence, dredged by Mr. G. M. Dawson (G. S. B.).
Fossil. — Montreal and Portland, N. America.

63. C y there auclax* n. sp.
(PI. xvii., figs. 14, 15.)

Shell, seen from the side, subovate, greatest height anterior, subequal to half
the length ; anterior extremity very broadly rounded ; posterior much narrower,
also well rounded ; dorsal margin nearly straight, slightly and gradually declining
backwards from the front ; ventral margin overhung centrally by the protuberance
of the shell, the marginal spines of which are seen here protruding. Valves much
depressed in front, and here furnished with a marginal fillet, then suddenly swelling
into a large protuberance, which occupies the greater part of the shell, and
suddenly forms a declivity to the posterior margin, while, as already stated, it
overhangs the ventral; round all the margins situated just within them but
projecting beyond is a series of blunt flattened spines, which sometimes show a
tendency to become bifid at the tip ; these spines are easily abraded, and no one
specimen has them all perfect ; along the ventral edge of the protuberance runs
a similar series of large size, and within this again, and parallel to it, passes
another row of spines, the hinder ones of this series being often long and acute ;
over the remaining parts of the surface there are small scattered spinules. Seen
from above, the tumidity is very great, the chief expansion behind the middle,
and the upper lateral row of spines is seen surmounting this tumidity ; at the
posterior extremity the sides suddenly but roundly converge, the extremity
itself being mucronate ; towards the front the narrowing of the valves is more
gradual, and the extremity acuminate. Anterior and posterior teeth of the hinge
well developed. Length, 1*2 mm.

Dredged by the "Valorous," in 1875, Stat. 12, lat. 56° 11', N. long. 37° 41
W., in the North Atlantic, in 1450 fath. among Globigerina ooze (A. M. N.).

* Audax " Valorous," the name of H. M. Steamship by which the species was dredged.

TRANS. ROY. DUB. SOC- , N.S. VOL. IV., PART IX.

'A

168 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

64. Cy there mirabilis, Brady.

1868. Cythere mirabilis, Brady, Mori. rec. Brit. Ostrac, p. 415, pi. xxix., fig. 7, 8.
1874. Cythere mirabilis, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 167, pi. viii., figs.
22-26; pi. xv., figs. 13-16.

One valve only was recorded as British in the " Monograph." This was found
in Admiralty soundings, taken off Lumpan Head, Lewis (G. S. B.). It has
not since been met with in our seas.

Distribution. — Ginevra Bay, Spitzbergen, Mr. Lamont's dredgings (G. S. B.).

Fossil. — By no means rare in the post-tertiary deposits of Scotland ; England
(Bridlington).

65. Cythere dunelmensis (Norman).
(Synonym. — C. horrida, G. 0. Sars.)

1868. Cythere dunelmensis, Brady, Mon. rec. Brit. Ostrac, p. 416, pi. xxx., figs. 1-12.
1874. Cythere dunelmensis, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 168, pi. v.,
figs. 13-20 ; pi. xi., figs. 36, 37.

Additional localities. — Dredged off the north of Scotland ; Kilchattan Bay,
Bute ; Firth of Forth, and coasts of Durham and North Yorkshire ; Loch
Long, Roseneath and Rothesay Bays, Firth of Clyde (Gr. S. B. and D. R.) ; Haaf,
Shetland ; off Valentia, Ireland (A. M. N.) ; Rockport, Co. Down (Malcomson).

Distribution. — Christiania Fiord, 6—20 faths., and Lofoten Islands, Norway
(G. 0. Sars) ; Stoksund, near the mouth of the Hardanger Fiord Norway, 126
faths. (A. M. N.); Iceland; Baffin's Bay; Deevie Bay, Spitzbergen, Mr.
Lamont's dredgings (G. S. B.).

Fossil. — England (Bridlington) ; Scotland, common ; Ireland (Belfast and
Woodburn).

66. Cythere antiquata (Baird).

1868. Cythere antiquata, Brady, Mon. rec. Brit. Ostrac, p. 417, pi. xxx., figs. 17-20.

1874. ( 'ythere antiquata, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 170, pi. xii., figs. 8-10.

1885. Cythere antiquata, Cams Prod. Faunae Mediterraneaa, p. 301.

Additional localities. — Dredged in the Firth of Forth ; Loch Ryan, and several
places in the Firth of Clyde; Breydon Water, Norfolk; Rivers Bure and Thames ; and

of the North Atlantic and North -Western Europe.

169

off Eddystone Lighthouse, and Scilly Islands ; the Mumbles, near Dublin, Birturbuy
and Westport Bays, Ireland (G. S. B. and D. R.); Dartmouth Harbour; off
Valentia, Ireland (A. M. N.); Irish Sea, 15-60 faths. ; Belfast Lough; Rockport,
Co. Down ; Island Magee, N. E. Ireland (Malcomson).

Distribution. — Messina (Seguenza) ; Naples (A. M. N.) ; Eastern Mediterranean;
Piraeus, Tenedos, Besika Bay, Constantinople, Jaffa (Gr. S. B.); Fosse de Cap
Breton, Bay of Biscay, 30-60 fath. (A. M. N.).

Fossil. — Scotland (Oban), Ireland (Belfast New Docks), Calabria, Sicily.

67. Cy there white/' (Baird).

1868. Cythere ivhitei, Brady, Mon. rec. Brit. Ostrac, p. 416, pi. xxx., figs. 21-24.

1874. Cythere ivhitei, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 169, pi. xii., figs. 1-3.

1885. Cythere whitei, Carus, Prod. Faunae Mediterraneae, p. 301.

Additional localities. — Dublin Bay; Kilchattan Bay, Bute; Girdler Sand, estuary
of Thames (G. S. B. and D. R.); Unst Haaf, Shetland; Dartmouth Harbour
(A. M. N.); Island Magee, N. E. Ireland, tide-marks (Malcomson).

Distribution. — Eastern Mediterranean at Jaffa; Syria; Gulf of St. Lawrence
(G. S. B.); Naples (A. M.N. ).

Fossil. — Belfast (New Docks).

68. Cythere jonesii (Baird).

Synonyms: Cythereis fimbriata, Norman; Cythere ceratoptera, Bosquet; Cythere
spectabilis, G. 0. Sars ; C. subcoronata, Brady [yix Speyer) ; Cythereis cornuta^
Jones {junior).

1868. Cythere jonesii, Brady, Mon. rec. Brit. Ostrac, p. 418, pi. xxx., figs. 13-16.
1874. Cythere jonesii, Brady, Crosskey, and Eobertson, Mon. Post-tert., Entom., p. 171, pi. xii., figs. 4-7.
1878. Cythere jonesii, Brady, Ostrac. Antwerp Crag, Trans. Zool. Soc, vol. x., p. 395; pi. Ixvii., figs.
2a-d.

1885. Cythere subcoronata, Carus, Prod. Faunaa. Mediterraneae, p. 301.

Additional localities. — Dredged off north coast of Scotland ; many places in the
Firth of Clyde ; off the Durham coast ; Birturbuy Bay, and Mulroy Lough,
Ireland; and off the Eddystone Lighthouse (G. S. B. and D. R.); off Tarbert,
25 fath., and Skipness, 41 fath. in Loch Fyne ; Killary Bay, and off Valentia,
112 fath., Ireland (A. M. N.).

Z 2

170 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Distribution. — Christiania Fiord (G. 0. Sars); off Sartoro, in Bergen Fiord,
15 fath. ; and Solems Fiord, Floro, 50—60 fath., Norway, only a single valve in
each locality (A. M. N.); Ginevra Bay, Spitsbergen, Mr. Lamont's dredgings ;
Bay of Biscay; Besika Bay, 14 fath.; Levant; the var. ceratoptera, Fosse de
Cap. Breton, 35 fath., Marquis de Folin (G. S. B.); Messina (Seguenza).

Fossil. — Ireland (Post-tertiary) var. ceratoptera, England, Suffolk (Pliocene),
Belgium and France (Eocene).

Genus III. — Limnicythere, Brady.

Acanthopus, Vernet.

[Type, L. inopinata (Baird).]

1. Limnicythere inopinata (Baird).

(Plate xvii., figs. 18, 19; var. compressa.)

1868. Limnicythere inopinata, Brady, Mon. rec. Brit. Ostrac, p. 419, pi. xxix., figs. 15-18.
1874. Limnicythere inopinata, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 173, pi. x.,
figs. 8-11 ; pi. xxxviii., fig. 9 ; pi. xxxix., fig. 1.

Generally distributed in ditches, lakes, and slowly running streams throughout
the British Islands ; found also not uncommonly in estuarine localities, and some-
times dredged at sea, though in these cases it has probably been washed down out
of fresh water. We figure a very remarkable form, var. compressa, in which the
extremities of the shell are produced, and flattened to an extraordinary degree ;
it was taken in Whitefield Loch, Wigtonshire (A. M. N.).

Distribution. — Sweden (Lilljeborg in Coll. A. M. N.) ; rivers Scheldt, and Maas
(G. S. B.).

Fossil. — Scotland, England.

2. Limnicythere relicta, Lilljeborg.
(Plate xvii., figs. 8, 9.)

1862. Cythere relicta, Lilljeborg, Ofversigt af K. Vet. Akad. Forband, p. 391, pi. i., figs. 1-17.

1879. Acanthopus elonyatus, Vernet, Materiaux pour servir a l'etude de la Faune profonde du Lac

Leman, p. 516, pi. xxviii., figs. 14-19.
1883. Limnicythere relicta, Lilljeborg, Internat. Fisheries Exbib. Lond., Sweden Catalogue, p. 147.

Shell of female long-ovate, ventricose, greatest height anterior, height less
than half the length ; well and broadly rounded at the extremities ; dorsal margin

of the North Atlantic and North -Western Europe.

171

nearly straight, posterior declination the longer ; ventral margin deeply sinuated
centrally. Seen from above, ovate, with a deep groove on each side where the
greatest breadth (had the sides continued evenly there) would have been ; extre-
mities mucronate, the anterior the more extended. Valves thin and fragile,
greyish-white, everywhere densely hispid ; at both extremities, especially the
anterior and along the dorsal line, the valves are much compressed, centrally they
are gibbously tumid, the tumidity divided above towards the dorsum by a deep
transverse depression. On the flattened extremities are seen many (10-12 or
more) radiating lines, which when they reach the margin terminate in long setose
hairs. Length, "6 mm.

Shell of the male very like that of female, but shorter and more ventricose.
The nail of the third pair of feet is very long, almost setiform, and twice as long
as the nail of the other feet.

The description and figures are taken from some of Lilljeborg's type specimens
in A. M. N.'s collection.

L. relicta has not yet been found in the British Isles. Its habitats, as far as
known, are Upsala, Sweden (Lilljeborg), and the Lake of Geneva (Vernet).

3. Limnicythere sancti-patricii, Brady and Robertson.
(Plate xvii., figs. 1, 2.)

1869. Limnicythere sancti-patricii, Brady and Eobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii.,

p. 17, pi. xviii., figs. 8-11 ; pi. xxi., fig. 4.
1874. Limnicythere sancti-patricii, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 174,

pi. ii., figs. 1-3.

Shell, as seen from the side, reniform, higher at the extremities than in the
middle, greatest height anterior, equal to half the length ; extremities well rounded
and entirely destitute of serratures, the anterior slightly the larger; superior
margin almost straight ; inferior deeply sinuated in the middle. Seen from above,
the outline is irregularly rhomboidal, widest somewhat behind the middle ; ex-
tremities acuminate ; greatest width rather less than the height. Seen from the
front, the outline is widest at the base, with gradually converging sides and broadly
arched apex ; ventral border convex and prominently keeled in the middle. Surface
of the valves sculptured with closely-set, polygonal excavations, and marked across
the middle with a wide and deep sinuous furrow, in front of which is another of
similar character but smaller ; behind the posterior furrow the shell rises towards
the ventral border in a prominent rounded eminence, the summit of which often
takes a tubercular form ; the ventral surface is furrowed in a longitudinal direction,
and also marked more or less with cross striae. Animal almost exactly like that of

172

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

C. inopinata ; abdomen slightly hirsute and produced into two lobes, each with a
short terminal seta. Length, "8 mm.

Habitat. — This is a larger and more robust species than L. inopinata or L. relicta ;
from the former it differs also in the absence of marginal serratures, and in having
usually a less wrinkled and more neatly-sculptured surface. The type specimens
were found in Lough Moher, about five miles south of Westport (county Mayo),
and more recently we have taken specimens in dykes near Whittlesea ; in the
Rivers Nene and Cam; and in Bishop's Loch, near Glasgow (G. S. B. and D. R.);
Whitetield Loch, Wigtonshire ; Lochs Ruter and Aber, Kirkcudbrightshire ; Lough
Neagh, Ireland (A. M. N.); Loch Fergus, Kirkcudbrightshire (G. S. B.).

Fossil. — England (Branston Fen, Lincolnshire).

The rounded eminence, often assuming a tubercular aspect, which is situated
near the ventral margin on the hinder part of the valves, seems to be a constant or
nearly constant character by which the species may be distinguished from its
congeners. It has, moreover, a peculiar aspect from the lesser central height of
the shell, which, while characteristic of the genus, is most strongly marked in this
species.

4. Limnicythere monstrifica (Norman).

1868. Limnicythere monstrifica, Brady, Mon. rec. Brit. Ostrac, p. 420, pi. xxix., figs. 9-12.
1874. Limnicythere monstrifica, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 175, pi. ii., figs.
8 a-d.

Additional localities. — Dykes at Whittlesea ; Breydon Water ; Rivers Cam at
Ely, and Ouse at Lynn (G. S. B. and D. R.).

Fossil. — England (Branston Fen, Lincolnshire).

Genus IV. — Cytheridea Bosquet.

[Type, Cytheridea Miilleri Von Minister.]
1. Cytheridea elongata, Brady.
Synonyms : Cythere angustata, Baird (nee Cytherina angustata, Miinster).

1868. Cytheridea elongata, Brady, Mon. rec. Brit. Ostrac, p. 421, pi. xxviii., figs. 13-16 ; pi. xl., fig. 6.

1869. Cytheridea cornea, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 18,

pi. xx., figs. 9, 10 {junior).
1874. Cytheridea elongata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 181, pi. ix., figs.
10-13.

Of common occurrence round the southern British coasts from low- water mark to
depths of 30—40 fath. ; occasionally also in estuaries and tidal rivers. It is much
scarcer as we proceed northwards.

of the North Atlantic and North-Western Europe.

173

Distribution. — St. Malo, Bay of Biscay ; Rivers Scheldt and Maas, Holland ;
Iceland ; Gulf of St. Lawrence (G. S. B.); Fosse de Cap Breton, 30-60 fath., and
Naples (A. M. N.).

Fossil. — Scotland, England, Ireland.

Type specimens in Dr. Norman's collection received by him from Dr. Baird
prove conclusively that C. elongata is the C. angustata of that author.

2. Cytheridea papillosa, Bosquet.
Synonyms : Cythere bradii and debilis, Norman ; Cyprideis bairdii, G. 0. Sars.

1868. Cytheridea papulosa, Brady, Mori. rec. Brit. Ostrac, p. 423, pi. xxviii., figs. 1-6 ; pi. xl., fig. 1.
1874. Cytheridea papillosa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 176, pi. vi.,
figs. 12-15.

1878. Cytheridea papillosa, Brady, Ostracoda, Antwerp Crag, p. 396, pi. lxii., figs. 1 a-d.

Additional localities. — Rothesay, Roseneath, and Greenock, in the Firth of
Clyde ; off the coasts of Durham and Yorkshire ; Westport Bay, Ireland ^G. S. B.
and D. R.); Shetland; off Valentia, Ireland (A. M. N.); Irish Channel and
Belfast Lough (Malcomson).

Distribution. — Abundant in Christiania Fiord, and as far north as the Lofoten
Islands (G. 0. Sars) ; Drobak, Lervig, Stoksund, Bergen, &c, Norway ;
Holstenbourg Harbour, and in Davis Strait, lat. 69° 31' N., long. 51° 1' W., 100
fath., and lat. 64 5' N., long. 56° 47' W., 410 fath.; "Valorous" Expedition
(A. M. N.); Hunde Islands, Baffin's Bay, 60—70 fath.; Iceland; Deevie Bay,
Spitzbergen, Mr. Lamont; Davis Strait; Gulf of St. Lawrence (G. S. B.).

Fossil. — Tertiary ; France and Belgium. Post-tertiary ; Scotland, England,
Norway, Canada.

3. Cytheridea punctillata, Brady.
Synonym: Cyprideis proxima, G. O. Sars.

1866. Cytherideis (?) pulchra, Brady, New and imperfectly known marine Ostracoda, Trans. Zool.

Soc, vol. v., p. 368, pi. lviii., figs. 3 a-c.
1868. Cytheridea punctillata, Brady, Mon. rec. Brit. Ostrac, p. 424, pi. xxvi., figs. 35-38; pi. ix., figs.
9-11.

1874. Cytheridea punctillata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 177, pi. vi.,
figs. 1-11.

1885. Cytheridea punctillata, Carus, Prod. Faunas Mediterraneae, p. 303.

Additional localities. — Dublin Bay ; Roseneath and Rothesay, in the Firth of
Clyde (G. S. B. and D. R.); Seaton Carew, Co. Durham (G. S. B.); Inverary and
off Tarbert and Skipness, in Loch Fyne ; off Valentia, Ireland (A. M. N.).

174 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Distribution. — Christiania Fiord, and thence to Fimnark(G. 0. Sars); Drobak,
Christiania Fiord (A. M. N.); Hunde Islands, Baffin's Bay, 28-40 fath., off Cape
Frazer, 80 fath. ; Spitzbergen, Mr. Lamont ; Iceland ; Gulf of St. Lawrence
(G. S. B.), lat. 60° 39' N., long. 3° 9' W., 203 fath., " Porcupine," 1869 (A. M. N.) ;
Messina (Seguenza).

Fossil. — Scotland, England, Ireland, Sicily.

4. Cytheridea stigmosa, n. sp.
(Plate xvi., figs. 21, 22.)

Shell subovate, highest near the front, greatest height rather more than half
the length ; anterior extremity higher than the posterior, well and evenly rounded ;
posterior extremity much narrower, well rounded ; dorsal margin arcuate throughout,
highest in front of the middle ; from this point backwards the declination is gradual
and even, and the convexity slight, while in front the slope is much more sudden,
though the convexity is much greater, the arcli here being bold ; ventral margin
very slightly sinuated in the middle. Seen from above, the outline is ovate, the
greatest breadth near the posterior extremity, which is rounded, while forwards
the sides gradually and slowly approximate, the anterior extremity being blunt and
scarcely acuminate. Surface of valves sculptured everywhere with little circular
pittings, which have a tendency to arrange themselves into lines, more especially
round the margins ; there are also a few scattered, opaque white papillae,
which are conspicuous against the glassy and semi-transparent general structure of
the valves. Length, *3 mm.

Habitat.— OR Valentia, Ireland, 112 fath. (A. M. N.).

5. Cytheridea si?nilis, Brady.
(Plate xvii., figs. 26, 27.)

1869. Cytheridea similis, Brady, Les Fonds de la Mer. (vol. i., p. 147, pi. xiv., figs. 19, 20.

Shell, as seen from the side, subovate, its greatest height in the centre exceed-
ing half the length ; anterior extremity rounded, posterior obtusely rounded ;
dorsal margin arched ; ventral margin nearly straight. Seen from above, ovate,
constricted in the middle: behind this constriction is the greatest breadth.
Surface of valves finely punctate and furnished with a few small rounded tubercles.
Length, *88 mm.

Habitat. — Bay of Biscay, Marquis de Folin (G. S. B.).

of the North Atlantic and North -Western Europe.

175

6. Cytheridea torosa (Jones).

1868. Cytheridea torosa, Brady, Mon. rec. Brit. Ostrac, p. 425, pi. xxviii., figs. 7-12 ; pi. xxxix.,fig. 5.
1868. Cytheridea littoralis, Brady, Nat. Hist. Trans. Northurn. and Durham, vol. iii., p. 6.
1870. Cytheridea torosa, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. rv., vol. vi., p. 21, pi. viii.,
figs. 6, 7.

1874. Cytheridea torosa, Brady, Crosskey, and Bobertson, Post-tert. Entom., p. 178, pi. xv., figs. 11, 12,

and var. teres, pi. vii., figs. 1, 2.
1886. Cytheridea torosa, Cams, Prod. Faunas Mediterranean, p. 302.

1888. Cytheridea torosa, Dabl, Die Cytberiden der Westlich. Ostsee, p. 16, pi. i., fig. 31, pi. ii., figs.
32-48.

Additional localities. — Type, rivers Ouse, Deben, Stour, Thames, and throughout
the broads and dykes of the Fen district; Dungeness Bay; Westport Bay, Ireland
(G. S. B. and D. R.) ; Newport, county Mayo (A. M. N.). Var. teres, in the Firth of
Clyde ; common throughout the Fen district ; ditches on Cardiff Moor (G. S. B.
and D. R.) ; Crossens, Lancashire (A. M. N.) ; Ellesmere Canal, near Ellesmere,
Shropshire (G. S. B.).

Distribution. — In an estuary called Engervand, near Christiania (G. O. Sars),
Piraeus, Besika Bay, Hellespont, Smyrna, Latakie*, Beyrout, Jaffa, Port Said, Sea
of Azov ; rivers Scheldt and Maas, Holland; Gibraltar; Adour Maritime, France
(G. S. B.), Western Baltic (Dahl).

Fossil. — Crag : Woolwich and Isle of Wight. Post-tertiary : Scotland, England,
South Wales, Ireland.

7. Cytheridea castanea, Brady.
(Plate xxi., figs. 3, 4.)

1870. Cytheridea castanea, Brady, Les Fonds de la Mer., vol. i., p. 117, pi. xiii., figs. 19-21; and pi.
xiv., figs. 1, 2.

Shell seen from the side elongated, subovate, highest near the front, height
equal to half the length ; anterior extremity rounded, bordered below the middle
with six short, blunt teeth ; posterior extremity obliquely rounded and somewhat
narrowed, bearing at the ventral angle a large, slightly-curved and sharp spine ;
dorsal margin forming a flattened arch, which is obscurely angulated in front of
the middle, curved very gently, except posteriorly, where it slopes steeply. Seen
from above, elongate-ovate, much more than twice as long as broad, widest in the
middle ; subacute in front, moderately broad and well-rounded behind, where it
is slightly emarginate in the middle, and uneven, owing to the lesser size of the

TRANS. EOT. DUB. SOC, K.S. VOL. IV., PART II. 2 A

176 Brady and Norman — Monograph of the Marine and Frcshivater Ostracoda

right valve. Shell-surface smooth, beset with numerous small rounded papillae.
Colour, reddish brown. Length, ] \3 mm.

Distribution. — Dredged by the Marquis de Folin in the Bay of Biscay (G. S. B.).
Port Said, Marquis de Folin (G. S. B.). The figures and decription now given are
from Mediterranean specimens. We have had no opportunity of re-examining the
Bay of Biscay specimens.

8. Cytheridea lacustris (G. 0. Sars).

1868. Cytheridea lacustris, Brady, Mon. rec. Brit. Ostrac, p. 472, pi. xxvi., figs. 18-21 ; and pi. xi.,
fig. 2.

1874. Cytheridea lacustris, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 179, pi. vi., figs.
1G-20.

1879. Acanthopus resistans, Vernet, Materiaux pour servir a l'etude de la Faune profonde duLac Leman,
p. 509, pi. xxvii., figs. 1-13.

The anatomical details given by Dr. Vernet in his notice of Acanthopus are
precisely those belonging to the genus Cytheridea, and a renewed dissection of two
species — C. lacustris and C. papillosa — since seeing Dr. Vernet's paper, leaves us
unable to find any distinctions of generic importance. We have not, however, as
yet succeeded in finding the male of C. lacustris.

Additional localities. — Loch Lomond ; the river Nene. at Peterborough, and the
Thames Estuary (G. S. B. and D. R.) ; Canal near Morningside, Edinburgh (D. R.) ;
Lough Neagh, Ireland (A. M. N.).

Distribution. — Norway (G. O. Sars); Lake Malar, Sweden (Lilljeborg in Coll.
A. M. N.).

Fossil. — Scotland, England.

9. Cytheridea (?) subjlavescens, Brady.

18G8. Cytheridea subjlavescens, Brady, Mon. rec. Brit. Ostrac, p. 429, pi. xxxiv., figs. 53-55.

Additional localities. — Near Rothesay, and in Loch Fyne (G. S. B. and D. R.);
off Tarbert, in 25 fath., and off Skipness, 40 fath. in Loch Fyne ; St. Magnus Bay,
Shetland ; the Minch, 45—60 fath. ; between the Cumbrae Islands, 15—25 fath.
(A.M.N.) ; Irish Channel, dredged ; and Belfast Lough (Malcomson).

It is a rare species, and when found is scarce, numerically The characters
are very constant, and well-marked/

of the North Atlantic and North -Western Europe.

177

10. Cytheridea fascis, n. sp.
(Plate xvi., figs. 23, 24.)

Shell, as seen from the side, broadly subtriangular, greatest height anterior,
equal to two-thirds of the length ; anterior extremity very broad, well and evenly
rounded ; posterior obliquely subtruncate, most produced at the infero-posteal
corner, where it is angled, thence the margin sweeps upwards and backwards
arcuately, the rise at first sudden, afterwards gradual, until the highest point of the
dorsal margin is attained in front of the middle, and from this point the forward
and downward sweep of the dorsal margin is well rounded and rapid to the anterior
extremity ; ventral margin (of the lateral edge of the shell, which assumes the
aspect of the ventral margin when seen from the side) very slightly convex
throughout the greater part of the length, until a small shallow sinus is reached,
which is situated just before the hinder extremity. Valves flat or rather hollowed
everywhere, except at the edges and where a rounded boss rises in the centre ;
surface uneven ; anterior margin furnished with 6-7 teeth, which curve forwards.
Colour glassy, semi-opaque, with scattered opaque white tubuli passing through
the shell to the surface. Notwithstanding the flattened surface of the valves, the
shell is extraordinarily thick, the sides rising perpendicularly from the margin, and
ultimately, at least in front, furnished at their summit with an overhanging edge ;
the thickness is excesssive at the extremities, and especially behind. Seen from
above, the outline is like that of a sheaf tied in the centre, with a knot appearing
on each side ; in front of and behind this knot is a constriction, and then the sides
diverge in both directions to broad truncate extremities, the hinder of which is, at
its termination, equal to half the length and two-thirds the height of the shell ;
while the somewhat narrower, though still very broad front extremity, has three
rib-like projections, a central formed by the junction of the valves, and on each
outer edge a lateral formed by the projected ledge of the upper lateral margin of the
valves, while broad rounded furrows occupy the interspaces of the riblets ; the outer
riblets are continued backwards, slightly converging, until near the centre of the
length of the dorsum they become effaced. The end view is in form a narrow
round-topped arch, with a bulbous projection in the outer side of the middle of the
lateral walls, base flat. Seen from below, the form is a long oblong, with nearly
parallel sides, but rather narrower in front, both extremities broadly and abruptly
truncate, a nodulous swelling near the middle on each side. Length, *8 mm.

Distribution. — This remarkable species was dredged by H. M. S. "Valorous,"
in Davis Strait, Stat. 6., lat. 64° 5' N., long. 56° 47' W., in 410 fath. (A. M. N.).

2 A 2

178

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

11. Cytheridea sorbyana, Jones.
Synonyms : Cytheridea dentata and inermis, G. 0. Sars.

1868. Cytheridea sorbyana, Brady, Mon. rec. Brit. Ostrac, p. 428, pi. xxix., figs. 1-6.
1874. Cytheridea sorbyana, Brady, Crosskey, and Bobertson, Mon. Bost-tert. Entom., p. 180, pi. vii.,
figs. 7-12.

Additional localities. — 80—100 fath., 20-25 miles N.N.W. from Burrafirth Light-
house, Shetland ; the Minch ; and 112 fath. off Valentia, Ireland (A. M. N.).

Distribution. — Stoksund,in Hardanger Fiord, Norway, in 80-100 fath. (A.M.N.) ;
Oxfiord, Finmark (G. O. Sars) ; Deevie Bay, Spitzbergen, Mr. Lamont, and off
Cape Frazer, 80 fath., Capt. Feilden in Nares' Arctic Expedition (G. S. B.).

Fossil. — Crag : England. Post-tertiary : England, Scotland, Norway, Canada.

Cytheridea incequalis, Brady and Robertson.

[The species, described by us under this name in " The Annals and Magazine of
Natural History" for 1870, was taken by the dredge in the river Cam, at Ely.
The probability is that the shell was a fossil one ; and on this account we prefer, for
the present, to withdraw it from the list of recent species.]

Genus V. — Eucythere, Brady.
= Cytheropsis, G. O. Sars.

[Type, Eucythere declivis (Norman).]

Eucythere declivis (Norman).

Synonym. — Cythcropsis tcnuitesta, G. O. Sars.

1868. Eucythere declivis, Brady, Mon. rec. Brit. Ostrac, p. 430, pi. xxvii., figs. 22-26, and 52-55.
1868. Eucythere argus (G. O. Sars), idem, ibidem, p. 431, pi. xxvii., figs. 49-51. (variety).

1868. Eucythere anglica, idem, ibidem, p. 475, pi. xxv., figs. 49, 50 (variety).

1869. Eucythere declivis, var. prava, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii.,

p. 18., pi. xxi., figs. 12-14.
1874. Eucythere anglica, Brady, Crosskey, and Robertson, Mon. Bost-tert. Entom., p. 183, pi. x., figs.
12-15 (variety).

On a careful re-examination of a large series of specimens belonging to this
genus, we are disposed to think that all ought to be referred to one species. That
the extreme forms of the series differ very considerably from each other, both in
form and surface-ornament, there can be no doubt; but there exist likewise number-
less intermediate forms which it is extremely difficult, or perhaps impossible, to

of the North Atlantic and North -Western Europe.

179

assign with accuracy if more than one specific form be allowed. We do not see
how the two forms described under the specific names argus and anglica can
with propriety be retained as separate species. They are, in all probability,
local and depauperized forms of declivis. The declivis and argus forms are very
generally distributed round the British Islands, ranging usually between 15 and
40 fath. We have not been fortunate enough in any case to meet with shells
containing the animal in a state sufficiently perfect for dissection.

A more remarkable variety than any yet described has been found by
A. M. N. on the Shetland Haaf. It is of very large size (*7 mm.), side outline as
usual, but gradually increasing in tumidity from behind forwards, until, at a
short distance from the anterior extremity, it becomes extremely gibbous above,
while the ventral margin below the gibbosity and the anterior extremity itself
are depressed ; the anterior extremity is much broader in proportion than in
specimens of lesser size, and is obliquely rounded ; the surface of the gibbous
portion is more or less sculptured with a raised reticulation. Viewed dorsally, the
breadth in front of the middle is greater than half the length, and the angle
formed by the united valves in front is almost a right-angle.

This species is almost ubiquitous in the British seas, ranging usually from
about 4 to 40 fathoms.

Distribution. — Christiania Fiord, and thence to the Lofoten Islands and Finmark
(G. 0. Sars), Christiania, Hardanger, and Oster Fiords, Norway ; Fosse de Cap
Breton, Bay of Biscay, 180—200 fath. ; off Isle of Capri, and at Naples (A. M. N.);
Gulf of St. Lawrence (G. S. B.).

Fossil. — Scotland, South Wales, Ireland, Norway, Canada.

Genus VI. — Krithe, Brady, Crosskey, and Robertson.
= Ilyobates, G. O. Sars.
[Type, Krithe bartonensis (Jones).]
1. Krithe bartonensis (Jones).

1856. Cytherideis bartonensis, T. E. Jones, Mon. Tert. Entoin., p. 50, pi. v., figs. 2 a-b and 3 a-b.
1865. Ilyobates preetexta, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 60.

1868. Ilyobates bartonemis, Brady, Mon. rec. Brit. Ostrac, p. 432, pi. xxxiv., figs. 11-14 ; and pi. xl.,fig. 5.
1874. Krithe bartonensis, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 184, pi. ii.,
figs. 22-26.

1880. Krithe bartonensis, Brady, Report " Challenger," Ostracoda, p. 113, pi. xxvii., figs. 2a-d.

Additional localities. — Off North coast of Scotland ; Roseneath and Rothesay, in
the Firth of Clyde; off the coasts of Durham and North Yorkshire (G. S. B. and

180 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

D. R.), Inverary, and off Tarbert, Loch Fyne, 25 fatli. ; off Valentia, Ireland
(A. M. N.).

Distribution. — Christiania Fiord, 6-20 fath., and thence to Lofoten Islands,
40-50 fath. (G. 0. Sars), Drobak, 30-100 fath. ; Hardanger Fiord, 210 fath. ;
Oster Fiord, West Norway, 100-200 fath. ; Fosse de Cap Breton, Bay of Biscay,
180-200 fath. (A. M. N.) : " Challenger," off the Ki Islands (between Australia
and New Guinea), 580 fath., Stat. 191; and off Christmas Harbour, Kerguelen
Island, 120 fath., Stat. 149 (G. S. B.).

Fossil. — Scotland, England, Norway, Calabria (Seguenza), var. monosteracensis.

This species is extremely variable. In some Norwegian examples the shell
is so produced as to be three times as long as the height, and the dorsal margin
so evenly and equally arched throughout that there is no posterior truncation,
though the infero-posteal angle remains ; in other narrow male forms the infero-
posteal angle is exserted, and forms a little rostrum ; while in some female forms
the shell is so much shorter than usual, that the outline closely corresponds with
that of Kritlie glacialis, except that the supero-posteal portion of the shell is not
quite so much protruded, and is rounded without angularity.

2. Krithe pro ducta, Brady.
(Plate xvii., figs. 5—7.)
1880. Krithe producta, Brady, Keport " Challenger," Ostracoda, p. 114, pi. xxvii., figs. 1 a-y.

Shell of female more flexuous and more tumid than that of Krithe lartonensis.
Seen from the side, subreniform ; greatest height situated in the middle, and equal
to more than half the length ; anterior extremity well and evenly rounded,
posterior obliquely subtruncated, rounded off above, and obscurely angulated
below, often slightly sinuated above the middle ; the margin itself below the
middle of the valve is not seen, being incurved and hidden under a projecting lip
which ends at the ventral angle; dorsal margin boldly arched, ventral almost straight.
Seen from above, ovate, widest in the middle, width equal to quite half the length,
pointed in front, wide, truncate, and central^ deeply emarginated behind. Surface
of valves quite smooth, or beset with numerous minute, closely-set punctures, and a
few distant circular tubercles. The shell of the male is much narrower and more
elongated. The foregoing description applies to the left valve, the right valve
differs considerably in outline, and is narrower behind. Length of female,
11 mm. ; of male, 1*3 mm.

Distribution. — This is extensive. " Porcupine" Expedition, 1869, Stat. 19, lat.

of the North Atlantic and North -Western Europe.

181

54° 53' N., long. 1(T 56' W., 1360 fath. ; Stat. 74, lat. 60° 39' N., long. 3' 9' W., 203
fath. " Valorous" Exped., 1875, Stat. 12, lat. 56° 11' N., long. 37° 41' W., 1450
fath (A. M. N.). The following are the places in which it occurred in the " Chal-
lenger" Expedition: — Three in the North Atlantic (Stats. 70, 76, 85), ranging
from lat. 28° 42', to 38° 25' N., and long. 18° 6' to 35° 50' W., in 900 to 1675
fath. ; one South Atlantic (Stat. 120), lat, 8° 37' S., long. 34° 28' W., 350 fath. ;
also midway between the Cape of Good Hope and Kerguelen Island ; off North
Brazil ; off Prince Edward's Island, and off Sydney (G. S. B.).

3. Krithe angusta, n. sp.
(Plate xvii., figs. 10-13.)

Shell of female narrow, oblong ; seen from the side, of nearly equal height
throughout; anterior margin well and evenly rounded, posterior obliquely
rounded, without angularity above or below ; dorsal margin straight ; ventral
sinuated rather in front of the middle; greatest height scarcely more than one-
third the length. Seen from above, narrow, cuneiform ; greatest width posterior
less than one-third of the length ; gradually tapering forwards to an acute extremity ;
posterior extremity rounded (without the characteristic emargination of the genus).
Shell of male more produced than that of the female, greatly elongated, of nearly equal
height throughout, but slightly higher in front ; greatest height less than one -
third the length ; anterior, dorsal, and ventral margins as in female ; posterior
more oblique, no angle above, but infero-posteal corner produced, the point
rounded ; the usual lip of the genus only slightly indicated. Seen from above, of
the same shape as, but still more compressed than, the female ; greatest width equal
one-fourth the length; posterior extremity narrowly subtruncate, but not
emarginate. Valves transparent, glossy, with a few scattered opaque white
specks, and the extremities ornamented with a series of radiating white tubes,
which traverse the substance of the shell. Length, -4 mm.

Although we have not taken these assumed S and ¥ together, nor examined
the animals, yet, from analogy, there seems to be every reason to suppose that they
represent the two sexes of one species. Numerically, the species is very scarce,
and easily overlooked on account of its small size. It has certainly nothing to do
with the young of K. bartonensis, which are short, high, obese, and remarkably
truncate behind.

Habitat. — Female: Oster Fiord, West Norway, 100—375 fath.; off Sartoro,
Bergen Fiord, 15— 40 fath. Male: Drobak, Christiania Fiord, 100 fath.; Har-
danger Fiord, off Stordoen, 210 fath. It has only as yet been found in the
Norwegian seas (A. M. N.).

182 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

4. Krithe reniformis (Brady).

(Plate xxi., figs. 23, 24.)

18C8. Paradoxostoma (?) reniforme, Brady, Contrib. to Study of Entornostraca, Ann. and Mag. Nat. Hist.,
ser. iv., vol. ii., p. 224, pi. xv., figs. 1, 2.

Shell, seen from the side, elongated, elliptical, of nearly equal height through-
out ; greatest height at the anterior extremity, and equal to about two-fifths of
the length ; anterior extremity very broadly and evenly rounded, point of
greatest projection central; posterior extremity nearly as broad as the anterior, its
upper portion is obliquely cut away, but the extremity itself is rounded, the point
of greatest projection being nearly central; dorsal margin perfectly straight in all
its central portion, and without arcuation behind ; sweeping down obliquely to the
extremity, but in front the downward slope is well-arched ; ventral margin with
a short but rather deep sinuation in front of the middle ; both before and behind
the sinuation the margin is gently convex. Seen from above, the form is slightly
cuneate, the greatest breadth rather less than the height, situated behind the
middle ; sides converging gradually in front to an acute extremity ; behind they
are rounded, and meet much more suddenly, so that the extremity is rather blunt.
Valves thin, glassy, and pellucid, dotted with opaque white specks. Length,
•50 mm.

The type specimens were found by G. S. B. in sand from Tenedos ; it has since
been dredged by A. M. N. in 180—200 fathoms, in the Fosse de Cap Breton,
Bay of Biscay, and in shallow water at Naples. From an examination of these
specimens we find that the3r belong to the genus Krithe.

5. Krithe glacialis, Brady, Crosskey and Robertson.

1874. Krithe glacialis, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entorn., p. 184, pi. vi., figs.
21-26.

Shell of female, as seen from the side, subrhomboidal, almost equal in height
throughout ; height equal to half or sometimes nearly two-thirds of the length ;
anterior extremity evenly rounded, posterior obliquely truncate, angled at junc-
tion with dorsal margin, and pointedly angled at junction with ventral margin ;
dorsal margin gently arched ; ventral slightly convex in front, nearly straight
behind. Outline, as seen from above, ovate, widest in the middle, acutely
pointed behind, rectangularly truncate in front, greatest width slightly exceeding

of the North Atlantic and North - Western Europe.

183

half the length, posterior extremity slightly emarginate at each side of the median
line. End view nearly circular. Shell of the male narrower and longer, dorsal
margin nearly straight ; ventral nearly straight, but slightly convex in front ;
infero-posteal angle more pronounced, the overhanging lip at the infero-posteal
portion of the shell (as usual in the genus) well developed. Shell surface smooth,
bearing several scattered circular papillae "and a few rather short thick hairs."
Lucid spots large, oblong, four in a transverse row a little below and in front
of the centre of the valve, and two or three a little in advance of the main
group.*

Length : female, '75 ; male, '95 mm. These measurements are taken from
fossil (Errol) examples. Our recent specimens are somewhat smaller.

Habitat.— u Porcupine " Exped., 1869 ; Stat, 41, lat. 49° 4'N., long. 12° 22' W.,
584 fath. (A. M. N.)

Fossil. — Scotland (Errol), Norway.

Genus VII. — Loxoconcha, G. O. Sars.
= Normania, Brady.
[Type, L. impressa, Baird.]
1. Loxoconcha impressa (Baird).

(Plate xxiil, fig. 7.)

Synonyms : Loxoconcha rhomboidea, G. 0. Sars (nec. C. rhomboidea, Fischer) ;

Cythere carinata, Brady.

1868. Loxoconcha impressa, Brady, Mon. rec. Brit. Ostrac, p. 433, pi. xxv., figs. 34-40; pi. xl., fig. 4.
1875. Loxoconcha impressa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 185, pi. viii.,
figs. 1-4.

1888. Loxoconcha rhomboidea, Dahl, Die Cytheriden der Westlich. Ostsee, p. 22, pi. ii., figs. 59-67. ; pi. iii.,
figs. 68-71.

This species is so universally distributed in the British seas, that it is needless
to add, as might be done very largely, to the already long list of localities given
in the "Monograph." It occurs in all sorts of situations, from dej^ths of 60 fath.
up to shallow estuaries, and in brackish and even fresh water ; as, for instance, in
the Belfast Canal, and in the rivers Deben at Woodbridge and Stour at Man-

* This is the usual arrangement of the lucid spots in the genus ; sometimes one or more in the
transverse row are constricted or divided (in K. producta, as figured in " Challenger " Beport, three
of them are completely divided) ; sometimes there are in addition one, two, or three scattered lucid
spots between the transverse row and the dorsal margin. All the above variations have been noticed in
K. producta.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. 2 B

184 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

ningtree. It seems, however, to be more abundant and more finely developed on
the southern and Atlantic than on the north-east coasts.

Distribution. — Coasts of Norway and Finmark, generally distributed (G. 0.
Sars and A. M. N.); Sweden (Lilljeborg) ; Germany (Zenker); Fosse de Cap
Breton, Bay of Biscay, 30-60 fath. ; Naples (A. M. N.) ; West Baltic (Dahl).

Fossil. — Scotland, Ireland, Norway, Calabria (Seguenza).

2. Loxoconcha guttata (Norman).

1865. Loxoconcha granulata, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 64.
1868. Loxoconcha granulata, Brady, Mon. rec. Brit. Ostrac, p. 434, pi. xxvi., figs. 51, 52.

1868. Loxoconcha guttata, idem, ibidem, p. 436, pi. xxvii., figs. 40-44.

1869. Loxoconcha granulata, idem, Nat. Hist. Trans. North, and Durham, vol. hi., p. 368, pi. xiii.,

figs. 5-7.

1874. Loxoconcha guttata, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 186, pi. viii.,
figs. 5-7.

1880. Loxoconcha guttata, Brady, Beport " Challenger," Ostracoda, p. 120, pi. xxix., figs. 1 a-f.
1885. Loxoconcha guttata, Cams, Prod. Faume Mediterranefe, p. 305.

L. guttata (Norman) was described from full-grown examples of the species of
which L. granulata is the condition in middle age. Young specimens are more
elongated in proportion to their height ; the surface is finely punctate, the edge of
the valves acute ; the shell, seen dorsally, has acute extremities. With increasing
age the punctations pass by degrees through smaller foveolse, until they become the
cells of the adult ; the margin of the valves also becomes more thickened, ultimately
appearing as a fillet, and the consequence of this is in full-grown specimens to
produce the aspect, when viewed from above, which is illustrated in fig. 41 of
the "Monograph."

Additional localities. — Off the North of Scotland; Firth of Forth; Clyde dis-
trict generally ; off Dungeness Bay, and of! Eddystone Lighthouse ; North
Yorkshire ; in the river Bure, Norfolk ; off Penarth Head ; Ilfracombe ; the
Scilly Isles ; Dublin, Clifden, Birturbuy, and Westport Bays, and Loughs Swilly
and Mulroy, Ireland (G. S. B. and D. R.) ; Inverary, and off Skipness in Loch
Fyne; theMinch; off Berry Head, in Start Bay, and Dartmouth Harbour, Devon;
Killary Bay, Co. Galway, and in Valentia Harbour, Ireland (A. M. N.) ; Irish
Channel and Belfast Lough (Malcomson).

Distribution. — Christiania Fiord, Norway, 10—12 fath. (G. O. Sars) ; Lervig
Bay, Stordoen, Norway ; Fosse de Cap Breton, Bay of Biscay, 30-200 fath. ; off
Isle of Capri, Mediterranean (A. M. N.) ; Vigo Bay, Spain, " Challenger;" and Port
Said (G. S. B.).

Fossil. — Scotland (Drip Bridge), Sicily.

of the North Atlantic and North -Western Europe.

185

3. Loxoconcha viridis (Miiller).

1785. Cythere viridis, Miiller, Entomostraca, p. 64, pi. vii., figs. 1, 2 [non Brady).

1853. Cythere viridis, Lilljeborg, De Crust, ex. Ord. tribus, p. 1C8, pi. xviii., figs. 4-6 ; pi. xix.,

figs. 3-5.

1854. Cythere da cida, Zenker, Monographie der Ostrac. (Archiv. fur Naturgescb.), p. 86, pi. iv. B.
1854. Cythere rhomboidea, Fischer, Abliand. d. Bayer. Acad. d. Wissensch. Bd. 7, p. 656 ( fide Lillje-
borg).

1865. Normania [/risen, Brady, Trans. Zool. So?., vol. v., p. 383, pi. lxi., figs. 10 a-e.
1868. Loxoconcha elliptica, Brady, Mon. rec. Brit. Ostrac, p. 435, pi. xxvii., figs. 38-39, 45-48 ; pi. xl.,
fig. 3.

1874. Loxoconcha elliptica, Brady, Crosskey, and Robertson, Mon. Post-tert Entom., p. 188; pi. xiv.,
figs. 23-25.

1885. Loxoconcha elliptica, Carus, Prod. Fauna? Mediterraneae, p. 307.

1888. Loxoconcha elliptica, Dabl, Die Cytheriden der Westlicli. Ostsee, p. 28, pi. hi., figs. 90-95, 99-106.

Additional localities. — A species restricted almost exclusively to brackish or
sub-brackisli situations, but in such places almost ubiquitous in the British Islands.
The following are recent additions to the list of habitats: — Near the mouths of
many Northumbrian rivers, and of the Humber and Deben ; also in the Broads
of Norfolk and Suffolk, and throughout the Fen districts ; Westport, Ireland
(G. S. B. and D. R.); Dartmouth Harbour; Newport, Co. Mayo (A.M. N.).

Distribution. — Sweden (Lilljeborg); Denmark (Miiller); Iceland; Holland, rivers
Scheldt and Maas (G. S. B.) ; Germany (Zenker), Cap Breton, Bay of Biscay
(A. M. N.); Mediterranean (Seguenza) ; Finland (Cajander.); West Baltic (Dahl).

Fossil. — Scotland (Govan), Wales, (Cardiff), Sicily (Seguenza).

The form grisea was described from an immature L. viridis. Similar examples
may usually be found in collections of that species which exhibit fully the various
stages of growth.

4. Loxoconcha multifora (Norman).

1868. Cythcropteron mnltiforum, Brady, Mon. rec. Brit. Ostrac, p. 449, pi. xxix., figs. 38-42.
1874. Loxoconcha multifora, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 187, pi. xiv.,
figs. 11, 12 a, b.

Though we have seen none but empty shells of this species, and are unable to
assign it with certainty to any genus, we are disposed to think that its affinities
are more with Loxoconcha than with Cytheropteron.

Additional localities. — Off north coast of Scotland ; Cumbrae and Rothesay
Bay; Budle Bay, Northumberland; off north Yorkshire coast; river Ouse, Norfolk ;
off Eddystone ; Ilfracombe ; Fowey Harbour, Cornwall ; Scilly Isles ; Clifden,
Birturbuy, and Westport Bays, Ireland (G. S. B. and D. R.); Start Bay, Devon;

2 B2

186 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Roimdstone Bay, Ireland (A. M. N.); Irish Channel and Belfast Lough
(Malcomson); 150 miles off the Land's End, 200 fath. (A. M. N.).

Distribution. — Off Sartoro, Bergen Fiord, 15—40 fath. ; Lervig Bay, Hardanger
Fiord, Norway, 10-20 fath. ; Fosse de Cap Breton, Bay of Biscay, 30-200 fath.
(A. M. N.) ; river Scheldt, Holland (G. S. B.).

Fossil. — Ireland (Portrush).

5. Loxoconcha pusilla, Brady and Robertson.
(Plate xvil, figs. 24, 25.)

1870. Loxoconcha pusil la, Brady and Robertson, Ann. and Mag. Nat. Hist., Ser. iv., vol. vi., p. 23, pi.
viii., figs. 1-3.

Carapace, as seen from the side, subrhomboidal, nearly equal in height through-
out ; height equal to half the length; extremities obliquely rounded ; superior and
inferior margins straight. Seen from above, the outline is regularly ovate, widest
in the middle, extremities nearly equally acuminate, width considerably less than
the height. Shell delicate and fragile, translucent, faintly rugose, and marked
also with a few scattered hairs and opaque white papillae. Length, '4mm.

Habitat. — Montrose Basin ; Firths of Forth and Clyde ; Budle Bay, Northum-
berland ; off Seaton Carew, Co. Durham, 4 fath. ; rivers Wansbeck, Blyth, Deben,
Ouse (Norfolk); Scheldt, Holland — scarce in all these places (G. S. B. and D. R.).
Westport, Ireland (A. M. N.) ; two miles N.E. of Muck Island, Irish Channel, 50
fath., and several places between tide-marks in Belfast Lough (Malcomson).

Its small size and peculiar shell-structure distinguish L. pusilla readily from
L. elliptica and L. tamarindus, with which alone it could be confounded ; moreover,
the young of the latter, when of the same size as L. pusilla, are subtriangular, one
end being much narrower, while the young of the former retain the elliptical form
of the adult, and are thus much higher in proportion to length than those of L. pusilla.

6. Loxoconcha tamarindus (Jones).
Synonyms : Cy there Icevata, Norman ; Loxoconcha lonyipes, G. O. Sars.

1868. Loxoconcha tamarindus, Brady, Mon. rec. Brit. Ostrac, p. 435, pi. xxv., figs. 45-48.
1874. Loxoconcha tamarindus, Brady, Crosskey, and Robertson, Mon. rec. Brit. Ostrac, p. 188, pi. viii.,
figs. 8-11.

1885. Loxoconcha tamarindus, Cams, Prod. Faunae Mediterranese, p. 306.

1886. Loxoconcha cunciformis, S (Brady MS.), Malcomson, Recent Ostracoda of Belfast Lough, Proc.

Belfast Naturalists' Field Club, p. 261, pi. xxv., figs, 1, 2.

One of the most abundant and widely-distributed of British Loxoconchce ; seldom,

of the North Atlantic and North-Western Europe.

187

however, in littoral situations. The long list of localities given in the " Mono-
graph " might be supplemented by others from almost all parts of the British and
Irish coasts.

Distribution. — In the Christiania Fiord, 20—30 fath., and thence to the Lofoten
Islands (G. 0. Sars); Lungegaards-vandet, Bergen; off Sartoro, 15-40 fath.; and
other places in the Bergen and Hardanger Fiords, Norway ; Cap Breton, S. W.
France (A.M.N.) ; Messina (Seguenza) ; Iceland; Pirseus (G. S. B.).

Fossil. — In the Crag of Suffolk (Jones). In Post-tertiary formations : Scotland,
Ireland, Norway, Calabria, and Sicily.

7. Loxoeoncha fragilis, G. 0. Sars.
(Plate xvii., figs. 32-34.)

1865. Loxoeoncha fragilis, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 65.
1870. Loxoeoncha fragilis, Brady and Eobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 24,
pi. x., fig. 3.

1874. Loxoeoncha fragilis, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 189, pi. xiv.,
figs. 30-32.

Shell of the female, seen from the side, subrhomboidal ; greatest height situated
in front of the middle, and equal to at least half the length ; anterior extremity
rounded, posterior produced in the middle into a short obliquely truncated process ;
superior margin moderately arched over the eyes, thence sloping gently back-
wards; inferior sinuated in the middle, convex behind. Seen from above, com-
pressed ; greatest width situated in front of the middle, and much less than the
height ; posterior extremity slender and produced. Valves excessively thin and
fragile, almost transparent, ornamented sparingly with very small tubercles, and but
slightly hairy. Margins produced, except on the dorsum, so as to form an en-
circling fillet, which is marked with radiating, hair-like lines. Shell of the male
narrower ; length equal to twice the height ; superior margin nearly straight and
horizontal; posterior extremity obtusely rounded below. "Antennas very
slender; second joint of the superior short, much shorter than the united lengths
of the two following, and shortly pilose on the anterior margin, last three joints
much elongated and nearly equal; third joint of inferior antennae very narrow, its
anterior margin smooth, without any setse. Feet very slender, second joint of the
last pair about equal to the conjoined length of the two following. Copulative
organs of the male obtusely produced in front. Eyes confluent." Length of
female, -5mm.

Habitat. — Montrose Basin, Greenock, and Firth of Forth, Scotland ; Budle

188 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Bay, Northumberland (G. S. B. and D. R.); off Valentia, Ireland, 112 fath.
(A. M. N.).

Distribution. — Christiania Fiord ; Lofoten Islands, rare (G. 0. Sars ; Lunge-
gaards-vandet, Bergen (A. M. N.).
Fossil. — Scotland.

Genus VIII. — Xestoleberis, G. O. Sars.
[Type, Xestoleberis aurantia (Baird).]
1. Xestoleberis aurantia (Baird).
Synonyms : Cythere nitida, Lilljeborg ; Cythere viridis, Zenker.

1868. Xestoleberis aurantia, Brady, Mon. rec. Brit. Ostrac, p. 437, pi. xxvii., figs. 34-37 ; pi. xxix., fig. 6.
1874. Xestoleberis aurantia, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 190, pi. xvi.,
figs. 32, 33.

Additional localities. — Cumbrae, in Firth of Clyde ; Northumberland Coast,
littoral but more common at the mouths of rivers ; estuaries of the Fen district and
Thames ; off Dungeness Bay ; off Eddystone and the Mumbles ; Ilfracombe and
Penarth Head ; Scilly Isles ; Dublin, Clifden, Westport, and Roundstone Bays, and
Lough Swilly, Ireland (G. S. B. and D. R<); Shetland; Head of West Loch Tar-
bert, Argyleshire ; Scarborough, Whitby, Robin Hood's Bay, and Filey Brig,
Yorkshire; Start Bay, Salcombe, and off Berry Head, Devon (A. M. N.); Irish
Channel, and Belfast Lough (Malcomson).

Distribution. — Norway ; Christiania Fiord, and thence to Lofoten Islands
(G. 0. Sars); Bergen and Hardanger Fiords (A. M. N.); Sweden (Lilljeborg);
Prussia (Zenker) ; rivers Scheldt and Maas, Holland ; Franklin Pierce Bay, lat.
79° 25' N., Capt. Feilden in Nares' Arctic Voyage (G. S. B.).

Fossil. — Scotland, South Wales, Ireland, Norway.

2. Xestoleberis depressa, G. O. Sars.

1850. (?) Cytherina tumida, Beuss, Foss. Entoin. Oesterr. Tert. Beckens, p. 57, pi. viii. , fig. 29.

1858. (?) Cytheridea tumida, Egger, Ostrak. Miociin-Scbicbt. Ortenburg, p. 17, pi. ii., fig. 11.

1868. Xestoleberis depressa, Brady, Mon. rec. Brit. Ostrac, p. 438, pi. xxvii., figs. 27-33.

1874. Xestoleberis depressa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 190, pi. vii.,
figs. 13-19.

1878. Xestoleberis depressa, Brady, Ostracoda of Antwerp Crag, p. 400, pi. lxvi., figs. 8 a-d.

1880. Xestoleberis depressa; Brady, Report " Cballenger " Ostracoda, p. 124, pi. xxxi., figs. 1 a-y.

1885. Xestoleberis depressa, Carus, Prod. Fauna? Mediterraneae, p. 308.

This species is so generally distributed, that it is needless to add to the list of
localities given in the "Monograph." It is found all round the British coasts in
depths varying from 2 to 50 fath., and even in greater depths.

of the North Atlantic and North- Western Europe.

189

Distribution. — Generally dispersed onNorwegian and Finmark coasts (G.O.Sars) ;
Bergen and Hardanger Fiords, many places (A. M. N.); Spitzbergen (G. S. B.);
Holstenbourg and Godhavn Harbours, Greenland; also in Davis Strait, lat.
69° 31' N., long. 56° V W., 100 fath., " Valorous" Exped. (A.M.N.) ; Bay of Biscay;
Gulf of St. Lawrence (G.S.B.) ; Messina (Seguenza) ; Kerguelen Island, 20-25 fath.,
and lat. 52° 4' S., long. 71° 22' E., 150 fath., "Challenger " (G. S. B.).

Fossil. — Crag : Antwerp. Post-tertiary : Scotland, Ireland, Norway, Canada,
Sicily, Calabria (Seguenza).

3. Xestoleberis labiata, Brady and Robertson.
(Plate xvi., figs. 27, 28.)

1874. Xestoleberis labiata, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. xiii.,p. 116,

pi. iv., figs. 8-15.
1885. Xestoleberis labiata, Carus, Prod. Faunae Mediterraneae, p. 308.

Shell of female, as seen from the side, oblong, subtriangular, highest in the
middle; height equal to rather more than half the length; anterior extremity narrow,
sharply rounded off ; posterior wide, obtusely rounded ; superior margin well
arched ; inferior nearly straight, but produced downwards towards the posterior
extremity into a bulging prominence. Seen from above, the outline is broadly
ovate, tapering rapidly in front to an acute point, and very broadly rounded
behind ; greatest width equal to the height, and situated behind the middle. The
shell of the male, seen laterally, is more slender and less tumid behind ; seen from
above, it is much more compressed and widest near the middle, the posterior
extremity being somewhat narrowly rounded. The surface of the valves is smooth,
distantly studded with small elevated round papillae. The chief peculiarity of the
species, however, is a remarkable labiate projection of the postero-inferior angle of
the shell, which is very conspicuous on the right valve. Length, '6 mm.

Habitat. — Scilly Islands, 14 fath. (G. S. B. and D. R.); Salcombe, Devon;
Falmouth (A. M. N.).

Distribution. — Messina, Sicily (Seguenza), off the Isle of Capri, Bay of Naples,
40 fath. (A. M. N.).

Fossil. — Sicily (Seguenza).

190 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

4. Xestoleheris margaritea, Brady.
(Plate xvi., figs. 25, 26.)

1865. Cytheridea margaritea, Brady, Trans. Zool. Soc, vol. v., p. 370, pi. lviii., figs. 6 a-d.
18G8. Xestoleheris intermedia, Brady, Les Fonds de la Mer, vol. i. (Gmc & 7me Livraisons), p. 94, pi. xii.,
figs. 3-7.

1880. Xestoleheris margaritea, Brady, Beport "Challenger" Ostracoda, p. 127, pi. xxx., figs. 2a-g.
1885. Xestoleheris margaritea, Cams, Prod. Faunas Mediterraneae, p. 307, $ .
1885. Xestoleheris intermedia, ibid, ibidem, p. 307, $.

Shell of female, tumid ; seen from the side ovate ; greatest height situated
behind the middle, and equal to two-thirds of the length ; extremities evenly
rounded ; dorsal margin moderately arched; ventral slightly sinuated in front of the
middle. Seen from above, the outline is broadly ovate, pointed in front, and well
rounded behind ; width equal to the height. End view obscurely angulated above,
broad and somewhat emarginate below. Surface of valves smooth, marked with
a few distant small papillae. Colour pearly-white, with translucent or milky
cloudings. Length, *5 mm. The male is longer and less tumid.

Distribution. — Bay of Biscay, Marquis de Folin ; Mediterranean ; Mauritius (?);
and by the " Challenger," Stat. 187, lat. 10° 36' S., long. 140° 55' E., 6 to 8fath.,
off Booby Island (G. S. B.).

Our figure is drawn from a specimen dredged in the Bay of Biscay, altogether
smaller and less tumid than the typical Mediterranean form, but in all other
respects agreeing closely with it. The form described by Dr. Brady as X. intermedia,
we now consider to be the male of X. margaritea.

Genus IX. — Cytherura, G. O. Sars.
[Type, Cytherura gibba (Miiller).]
1. Cytherura gibba (Miiller).
(Plate xvin., figs. 13-16, Plate xxn., figs. 6—12, and Plate xxiii., fig. 8.)

1785. Cytheregihha, Miiller, Entomostraca, p. 66, pi. vii., figs. 7-9, $ .
1785. Cythere gibbera, ibid, ibidem, p. 66, pi. vii., figs. 10-12, $ .

1853. Cythere gibbera, Lilljeborg, De Crust, ex Ord. tribus, p. 167, pi. xix., figs. 1,2, $ .

1854. Cythere gibba, Zenker, Monog. der Ostrac. (Arcbiv. fur Naturgescb.j, p. 84, pi. v., D. $ . $ .
1864. Cytherura gibba, G O. Sars, Oversigt af Norges marine Ostracoder, p. 70, $ . $ .

1868. Cytherura robertsoni, Brady, Mon. rec. Brit. Ostrac, p. 444, pi. xxxii., figs. 16-18, $ .
1874. Cytherura robertsoni, Brady, Crosskey and Robertson, Mon. Post-tert. Entom., p. 221, 3 . £ .
1880. Cythere gibba^Nilh. Miiller, Zeits. fur die Gesamm. Naturwiss.VL, p. 243, pi. v., figs. 7, 12, 13, <? $.
[now Cytherura gibba, Brady, Mon. rec. Brit. Ostrac]

Shell of female subovate, height in front and behind nearly equal, greatest
height subequal to half the length ; anterior extremity widely rounded, dorsal

of the North Atlantic and North -Western Europe.

191

margin nearly straight in the middle portion, ventral margin sinuated. Seen
from above, greatest width behind the centre. Shell of the male more elongated,
oblong; seen from above, sinuated on each side about the middle of the length.
Surface of valves punctate and very markedly and regularly reticulated with
a network of raised lines.*

So much of the description applies both to this and the following species.
C. gibba has the following additional characters, which distinguish it from
C. cornuta: —

In both sexes of C. gibba the beak at the hinder extremity is small, and in the
form of an inconspicuous central, rounded protuberance. The female has on each
valve, just behind the middle, and projecting outwards from the ventral margin, a
more or less conspicuous semiovate flattened lateral protuberance or ala. Seen
irom below, the widest part is behind the middle where the just-described lateral ala
forms a rounded prominence ; the outline tapers in front to a sharp extremity, while
the hinder end is broadly rounded, presenting only a minute median mucronate
point, so small that it can hardly be called a beak. The male, seen from the
side, instead of the flattened semiovate lateral ala of the female, has the posterior
portion of the shell regularly and evenly swollen into a rounded protuberance,
in front of which a constriction passes transversely across the valves. The reticu-
lation of the valves is much more elegantly developed in this species than in the
next. Colour, greenish-black, either concolorous, which it commonly is in the
female, or having a central transverse fascia, and the extremities of the shell
creamy white. Length of male, '55 mm. ; of female, '45 mm.

Habitat. — This is a typical brackish-water species, and often occurs abund-
antly in places where the admixture of saline ingredients is very slight.
The following partial list of habitats will suffice to show its wide distribution : —
River Clyde at Greenock ; Montrose Basin ; near the mouth of several
Northumberland rivers ; in the rivers Deben, Stour, and Ouse ; in many of the
Norfolk Broads; brackish pond at Westport, Co. Mayo ; canal at Belfast (G. S. B.
and D. E.); Head of West Loch Tarbert, Argyleshire; Seaton Sluice,
Northumberland ; Dartmouth Harbour ; Newport, Ireland (A. M. N.) ; ? Irish
Channel (Malcomson).

Distribution. — Norway (G. 0. Sars) ; Sweden (Lilljeborg ! ) ; Denmark (Miiller) ;
Prussia (Zenker) ; Pomerania (Willi. Miiller !) ; Finland (Cajander) ; rivers Scheldt
and Maas, Holland (G. S. B.).

Fossil. — Scotland (Loch Gilp), Norway.

:,; It is worth notice that the central areola, so characteristic of the shells of almost all Cythemra,
is not a mere pigment patch, but consists of denser and more resistant tissue than the rest of the valve —
perhaps a sort of defensive buckler over the central part of the animal. It offers more mechanical
resistance to pressure, and is less easily acted on by chemical re-agents. When treated with acid it is
often left entire after the rest of the shell has disappeared.

TRANS. ROY. DUB. S0C, N.S. VOL. IV., PAST II. 2 C

192 Brady and Norman — Monograph of the Marine and Freshwater Osracoda

2. Cytherura cornuta, Brady.
(Plate xviii., figs. 21, 22.)

18G8. Cytherura cornuta, Brady, Mon. rec. Brit. Ostrac, p. 445, pi. xxxii., figs. 12-15 $ .
18G8. Cytherura yibba, idem, ibidem, p. 444, pi. xxxii., figs. 68-70, $ {rum C. yibba, Muller).
18G8. Cytherura affirm, idem, ibidem, p. 443, pi. xxxii., figs. 19-21, $ variety (vix C. affinis, Sars).
18G8. Cytherura lineata, idem, ibidem, p. 441, pi. xxxii., figs. 30-34, 67 (junior).

1874. Cytherura cornuta, Brady, Crosskey, and Bobertson, Mon Post-tert. Entom., p. 199, pi. xiii., figs.
23-25, $.

1874. Cytherura yibba, iidem, ibidem, p. 198, pi. xiii., figs. 26-29, g .

1878. Cytherura cornuta, Brady, Ostracoda Antwerp Crag, Zool. Trans., vol. x., p. 402, pi. ixvi., figs.
9 a-k.

1885. Cytherura cornuta, Cams, Prod. Faunae Mediterranean, p. 309.

The male of this species was mistaken in the " Monograph " for that of C.
gibba, Muller, but the true C. gibba is the last species, which has generally been
known in this country as C. robertsoni.

The female, viewed laterally, is not unlike that of C. gibba, from which it may
be distinguished by the following characteristics. The posterior beak is much
more pronounced, and forms a large angular process situated rather above
the middle of the posterior extremity. There is no semi-ovate lateral ala, as
in C. gibba, but instead of this the ventral margin is acute, and at a short
distance above it on the side is a longitudinal rib, which, sometimes in the adult
and always in the young, terminates posteriorly in a spinous point, The outline,
seen from below, is pretty evenly ovate, the widest part being, if anything, in
front of the middle ; posterior extremity narrow, and having a conspicuous large
central beak. The male is distinguished from that of C. gibba by the keel or
rib, which, as in the female, runs along the side a little within the ventral
margin, but does not end in a spine ; the protuberance on the hinder part of the
shell is more prominent and boss-like than in the female ; the depression anterior
to this commences above the boss, and thence passes obliquely forwards and down-
wards ; the posterior rostrate process is much larger, and situated above the middle :
seen from below, the outline is cuneiform, the greatest breadth being close to the
posterior extremity; just in front of the rostrum the boss on each side projects
beyond and conceals the rib. Length of female, "40 mm. ; of male, "45 mm.

Cytherura lineata of the " Monograph " is the young condition of this species. In
early stages the outline approaches more and more towards a triangular form as the
age is less, the lateral rib terminates behind in a spine, and the surface sculpture
consists of longitudinal striae instead of the reticulation of the mature animal.

Additional localities. — Off the North coast of Scotland ; Loch Fyne, Loch Ryan,
and many places in the Firth of Clyde; off the Scilly Isles; Dublin, "Westport,

of the North Atlantic and North- Western Europe.

193

Clifden, and Roundstone Bays, and Mulroy Lough, Ireland ; between tide-marks
at Boulmer, Northumberland (G. S. B. and D. R.); Unst Haaf, Shetland; the
Minch; Inverary ; Berwick-on-Tweed ; Salcombe, Devon (A. M. N); Irish Channel,
and Belfast Lough (Malcomson).

Distribution. — Dardanelles (G. S. B.).

Fossil. — Scotland, Ireland, Norway.

3. Cytherura affinis, G. O. Sars.
(Plate xvm., figs. 19, 20.)
1865. Cytherura affinis, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 77.

Shell, seen from the side, somewhat oblong, greatest height not quite equal to
half the length ; anterior margin very broadly and evenly rounded ; posterior pro-
duced into a well-pronounced beak, which is situated above the middle, and has
its termination obliquely truncate ; dorsal margin forming a very low and depressed
arch, with a very slight angularity in front of the middle ; ventral margin scarcely
concave, the concavity evidenced chiefly in front where at its junction with the
anterior margin an angularity is formed. Valves very tumid below, where they
are projected outwards and form a sharply-keeled edge ; from this point of greatest
tumidity the sides abruptly converge, like the gable of a house, and meet acutely
above ; just in front of the middle in the region of the lucid spots, which form a
transverse row and are unusually near the ventral margin, there is a slight trans-
verse depression. Surface of valves more or less reticulated, and sculptured with
round puncta, which have a tendency to arrange themselves in longitudinal
lines. Seen from above, the outline is elongated-subovate, the width fully equal
to the height, the sides somewhat flattened, and obscurely sinuated in the position
of the transverse furrow already described ; in front the extremity is pointed, the
sides, rather rapidly and flatly converging, form at their union an angle of about
80 degrees ; behind they arcuately converge, and the rostrum forms a mucronate
projection. Seen from below, the base is very broad and remarkably flat, and
sculptured with longitudinal striee. Length, -6 mm.

Distribution. — As yet only known in Scandinavia, Oxfiord, Finmark (G. O. Sars),
Drobak, Christiania Fiord, 120fath. ; and off Midso Lighthouse, Hardanger Fiord,
50-100 fath. (A. M. N.).

Fossil. — Norway (G. O. Sars).

The young differ from the adult in being less high in proportion to the length,
the beak more central, the lateral ridge terminating behind in a spine-point, the sur-
face much more strongly reticulate than in the adult, and theriblets more raised. It

2 C 2

194 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

reminds us of the young of C. cornuta (= C. lineata, Brady), but is higher in pro-
portion to the length, and the sculpture different.

The shorter, higher, and more roundedly ventricose C. affinis of Brady, Mon.
PI. xxxii., figs. 19—21, is not the present species, but a variety of C. cornuta in
which the lateral rib is not developed behind.

4. Cytherura sella, G. 0. Sars.
(Plate xviii., figs. 3—6.)

1865. Cytherura sella, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 73, $ $ .

1868. Cytherura cuneata, Brady, Mon. rec. Brit. Ostrac, p. 442, pi. xxxii., figs. 35-38, 63, $ .

1869. Cytherura flavescens, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 49, pi. viii., figs.

13-15 $.

1869. Cytherura flavescens, idem, ibidem, vol. iii., p. 391, pi. xx., figs. 13, 14.

1874. Cytherura flavescens, Brady, Crosskey, and Robertson, Mon. Post.-tert. Entom., p. 193, pi. xi.,

figs. 43-46 and pi. xvi., figs. 7, 8.
1874. Cytherura cuneata, iidem, ibidem, p. 196, pi. xi., figs. 42-47 ; pi. xii., fig. 15 ; pi. xiii., figs. 36, 37.
1885. Cytherura cuneata, Cams, Prod. Faunae Mediterraneas, p. 309.

Female. — The lateral view is rhomboidal, but the height is equal to just half the
length, and the posterior beak is less prominent than in the male. Seen from above,
the shape is ovate, widest in the middle and tapering towards each extremity,
width decidedly less than half the length, anterior extremity acuminate, posterior
mucronate. The surface-sculpture is generally similar to that of the male, but the
lattice-work is much coarser, and the interspaces are not so delicately punctated.
Length, '43 mm.

Male. — Shell, seen from the side, subrhomboidal, height nearly equal throughout,
scarcely equal to half the length ; anterior extremity obliquely rounded ; posterior
produced about the middle into a short truncated or obtusely rounded beak,
sinuated below the middle ; superior margin almost straight or very feebly arched ;
inferior straight. Seen from above, the outline is wedge-shaped, greatest width
situated near the posterior extremity and equal to the height; subacuminate in
front, broadly mucronate behind. The surface is marked with distinct but delicate
longitudinal ribs and with sinuous cross bars, which are somewhat irregular in
distribution ; the interspaces of the reticulations are finely punctate, this pattern
being best seen on the posterior tuberosities of the shell. Length, '48 mm.

Specimens described in the " Monograph," as the female C. cuneata, are really
only a less slender form of the male. The true female had not then been seen,
and the few specimens of the female first subsequently found — lacking some of the
most conspicuous characters of the male as to shape and sculpture — were erroneously

of the North Atlantic and North -Western Europe.

195

referred to a new species, under the name of C. flavescens. The large series of speci-
mens which have of late years Come under our observation leave no room to doubt
the identity of the two forms, and wherever one occurs in abundance the other is
sure to be found in equal numbers.

Cytherura sella occurs plentifully all round the British Islands, ranging from a
depth of thirty fathoms or more up to low-water mark. It occurs also frequently
in estuarine situations.

Distribution. — Christiania Fiord, 3—8 fath., rare (G. 0. Sars) ; Lervig Bay,
Stordoen, and Stoksund, 126 fath. (A. M. N.); Iceland; rivers Scheldt and Maas,
Holland (G. S. B.) ; Fosse de Cap Breton, Bay of Biscay, 180-200 fath. (A. M. N.) ;
Eastern Mediterranean, Smyrna (G. S. B.).

Fossil. — Scotland.

5. Cytherura acuticostata, G. 0. Sars.

1868. Cytherura acuticostata, Brady, Mori rec. Brit. Ostrac, p. 445, pi. xxxii., figs. 1-11.
1874. Cytherura acicticostata, Brady, Crosskey, and Bobertson, Mon. Post-tert Entom., p. 199, pi. xvi.,
figs. 1-3.

1885. Cytherura acuticostata, Carus, Prod. Faunae Mediterraneaa, p. 311.

One of the commonest and most widely distributed species of the genus,
varying, however, very considerably in external appearance, so far as that depends
on the development of the characteristic surface-ridges and their spines.

This is one of the commonest and most abundant of British ostracoda, and must
be looked upon as a purely marine form, notwithstanding its occurrence in such
estuarine situations as the rivers Bly th, Humber, and Ouse, and even in fresh water
at Whittlesea Dyke. Its usual habitat is in the sea, ranging from about 4 fathoms
downwards. It is found at all points of the British coasts.

Distribution. — Christiania Fiord (G.O. Sars) ; Oster Fiord ; Batalden, near Floro ;
Bergen Fiord; Lervig Bay (A. M. N.) ; Messina (Seguenza); off Capri, Bay of
Naples (A. M. N.)

Fossil. — Scotland (Oban), Ireland (Belfast), Norway.

196 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

b. Cytherura striata, G. 0. Sars.
(Plate xviil, figs. 17, 18.)

1868. Cytherura striata, Brady. Mori. rec. Brit. Ostrac, p. 441, pi. xxxii., figs. 26-29, 62, 64, 65, $ .
1868. Cytherura quadrata, Norman, Last Report Dredging among the Shetland Isles, Brit. Assoc.
Report., p. 292, $ .

1872. Cytherura quadrata, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. ix., p. 55,
pi. i., figs. 10, 11.

1874. Cytherura quadrata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 195, pi. xi., figs.
38-41.

1874. Cytherura striata, iidem, ibidem, p. 196, pi. xiii., figs 34, 35.
1885. Cytherura striata, Carus, Prod. Faunae Mediterraneae, p. 310.
1885. Cytherura quadrata, idem, ibidem, p. 311.

The female (C. quadrata, Norman) differs from the male in being shorter and
higher, the ventral margin quite straight, the ala more developed, and the shell
more tumid, and when seen from above its greatest width is situated towards the
anterior extremity.

This is one of the commonest of the Cytherurce, occurring in tidal pools, as well
as in all depths of water round the British coasts, and extending commonly into
the estuaries of rivers on the east coast of England and in Holland. G. S. B.
and D. R. have found it also in freshwater dykes at Whittlesea. Any complete
list of habitats would have to include almost all our marine dredgings.

Distribution. — Christiania Fiord, 3— 8 fath. (G. O.&ars); Drobak, 30— 120 fath. ;
Haakelsund, Kors Fiord, 3—10 fath., and Lervig Bay, 10-25 fath., Norway
(A. M. N.) ; rivers Scheldt and Maas, Holland (G. S. B.) ; Messina (Seguenza) ;
Naples (A. M. N.).

Fossil. — Scotland, South Wales, Ireland, Norway, Canada, and Calabria.

7. Cytherura exserta, n./sp.

(Plate xx., figs. 24, 2,5.)

Shell, seen from the side, oblong ; height nearly the same throughout, equal to
two-fifths of the length ; anterior margin broadly and evenly rounded, greatest
protrusion central; posterior extremity with a very short beak situated slightly
above the middle, its termination broadly truncate ; dorsal and ventral margins
subparallel, the former arcuately declining in front, while the hinder slope is scarcely
convex ; the latter slightly concave. Valves compressed at the extremities, very

of the North Atlantic and North- Western Europe.

197

tumid throughout their central portion, but having a slight depression towards the
dorsal margin just in front of the middle, surface sculptured with longitudinal
riblets. Seen from above, the aspect is unlike that of any other Cytherura, the
central portion forms a short and very broad oval, the sides of which are very
convex ; greatest width much exceeding the height, and equal to more than
half the length ; beyond this oval the extremities are alike, the sides suddenly
converging are projected forwards (or backwards) and form mucronate points.
Length, -30 mm.

This is a very minute species, with strongly marked characters. Small as the
size is, the shells have nothing of the appearance of immaturity, but are strongly
calcareous.

Habitat. — Two specimens, dredged in 126 fath., in Stoksund, near the mouth
of the Hardanger Fiord, Norway, in 1879 (A. M. N.).

8. Cytherura angulata, Brady.
(Plate xix., figs 7, 8.)

1868. Cytherura angulata, Brady, Mori. rec. Brit. Ostrac, p. 440., pi. xxxii., figs. 22-25.

1870. Cytherura insolita, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. iii., p. 371,

pi. xiii., figs. 11, 12 (monstrositas).
1874. Cytherura angulata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 197, pi. xii.,

fig. 14 ; pi. xi., figs. 48-51.

C. angulata occurs in dredgings from all parts of the British Seas, and in all
depths of water from tide-marks to 30 fathoms ; numerically, however, it is
not by any means so common as many other species of Cytherura.

Distribution. — Norway, in the following places — Lervig, Stordoen, 3-25 fath. ;
Stoksund, 126 fath., and Drobak, 30-100 fath. (A. M. N.) ; rivers Scheldt and
Maas, Holland (G. S. B.).

Fossil. — Scotland, South Wales (Cardiff), Ireland, Norway.

9. Cytherura atra, G. O. Sars.
(Plate xvii., figs. 22, 23.)

1865. Cytherura atra, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 75.

1874. Cytherura similis, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 192 (partim), pi. xi.,
figs. 16-18.

Shell of female, seen from the side, obliquely quadrangular, or subrhomboidal ;
greatest height sub-equal to half the length ; anterior margin obliquely rounded,
posterior obliquely truncate, or produced above the middle into a very short and

/

198 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

obtuse process ; dorsal margin evenly arched ; ventral gently sinuated, with an
obtuse posterior angle. Seen from above, the form is ovate, greatest breadth
situated behind the middle, rather less than the height, gradually attenuated in
front and behind. Surface of valves distinctly and somewhat regularly reticu-
lated, no median areola. The whole shell remarkable for its deep black colour.
Antennae and antennules more robust than usual, terminal joint of the anten-
nules very short. Terminal nail of feet moderately large and strong ; second
joint of last pair rather longer than combined length of two following joints.
Male unknown. Length, "51 mm.

Habitat. — Very rare in the Lofoten Islands, in 3-8 fath. (G. O. Sars).

The above is Sars' description of the species, and the figures are taken from
one of his specimens in the collection of A. M. N.

Fossil. — Post-tertiary : Scotland (Loch Gilp, Barrie, &c).

10. Gytherura undata, G. 0. Sars.

(Plate xix., fig. 12 (junior).)
Synonym : Cytherura humilis, Brady.

1868. Cytherura wndata, Brady, Mon. rec. Brit. Ostrac, p. 443, pi. xxxii., figs. 43-49, 66.
1868. Cytherura juimila, Norman, Last Report Dredging among the Shetland Isles, Brit. Assoc. Report,
p. 392 (name only).

1874. Cytherura wndata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 194, pi. xi., figs.

9-15 ; pi. xii., fig. 17.
1874. Cytherura pumila, iidem, ibidem, p. 193, pi. xii., figs. 33-35 (junior).

A widely-distributed species, occurring in moderate depths of water all round
the islands, and reaching into the estuaries of rivers on the Northumberland coast ;
rarely found between tide-marks, but scarcely ever missing in dredged material
from the British coasts.

Distribution. — Christiania Fiord, 3-8 fath., and thence to Finmark (G. O. Sars);
Batalden, near Floro, 200 fath. ; Drobak, 120 fath. ; Lervig Bay, 10-25 fath. ;
Stoksund, 126 fath. ; Bukken, in Bergen Fiord, 40 fath. (A. M. N.); river Scheldt,
Holland ; Spitzbergen; Cumberland Inlet; Baffin's Bay, lat. 66° 10' N., long. 67° 15'
W., 15 fath. (G. S. B. and D. R.) : "Valorous" Expedition, Holsteinborg
Harbour, 10 fath., and Davis Strait, Stat. 3, lat. 69° 31' N., long. 56° 1' W.,
100 fath. (A. M. N.); Franklin-Pierce Bay, 13-15 fath., Capt. Feilden, in Nares'
Arctic Voyage ; Gulf of St. Lawrence (G. S. B.).

Fossil. — Scotland, Ireland, Norway, Canada.

We have come to the conclusion that Cytherura pumila of the Post-tertiary Mo-
nograph, which we here figure (PI. xix., fig. 12), must be regarded as the young
of this species. It has a very different shape from the adult ; the surface is
densely punctate all over ; at first one or two slight folds appear, and these

of the North Atlantic and North -Western Europe.

•199

gradually increase in size and number, until the strongly ribbed state of the adult
is attained. With the development of the ribs, there at the same time takes place
an overgrowth on all parts of the surface, which entirely obliterates all traces of the
punctation characteristic of the young shell.

11. Cytherura producta, Brady.
(Plate xix,, figs. 5, 6.)

1868. Cytherura producta, Brady, Mon. rec. Brit. Ostrac, p. 443, pi. xxxii., figs. 60, 61.
1874. Cytherura producta, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 198, pi. xiii.,
figs. 30-33.

Additional localities. — This is one of the less common species, occurring usually
in small numbers. Additional localities are Firth of Clyde, in several places ; off
the coasts of Durham and North Yorkshire; Dungeness Bay; off Eddystone
Lighthouse ; in the rivers Aln and Thames ; the Scilly Isles ; Westport and Round-
stone Bays, and Mulroy Lough, Ireland (Gr. S. B. and D. R..); Bressay Sound,
Shetland, tide-marks; off Tarbert, Loch Fyne, 25 fath. (A.M.N.) ; Irish Channel,
and Island Magee, near Belfast (Malcomson).

Distribution. — Off Sartoro, Bergen Fiord, 15—40 fath. ; and Lervig Bay,
Stordoen, Norway (A. M. N.); river Scheldt, Holland (Gr. S. B.).

Fossil. — South Wales (Cardiff New Dock Basin).

12. Cytherura yrosnlandica, n. sp.

(Plate xviii., figs. 23, 24.)

Shell, seen from the side, somewhat peach-stone shaped ; greatest height
central, more than half the length ; anterior margin subtruncate, or even slightly
emarginate, most produced below the middle ; posterior extremity with a well-
pronounced, sub-central beak, which has its termination obliquely truncate ; dorsal
margin boldly arched, anterior declination much arched, posterior slope scarcely
convex ; ventral margin slightly sinuated in front, no angulation at its junction
with the anterior margin, the margin behind the anterior sinuation is boldly
convex. Valves moderately, and tolerably evenly convex, without angularity
below, and not forming an acute ridge at their junction dorsally, as is the case in
C. affinis, which the present resembles in its combination of reticulation
and punctation of the surface sculpture. Seen from above, the greatest width,
which is much less than the height and sub-equal to two-fifths of the length, is
posterior, the sides thence at first very slowly, but at two-thirds the length more

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. II. 2 D

200 Brady and Norman — Monograph of the Marine and Freshivater Ostracoda

rapidly but still gradually converge, in such a way that the anterior extremity is
conical, with well-rounded and wide termination ; behind the valves converge with
an abrupt arcuation, and the rostrate process forms a small mucro. Viewed from
below, the base is of moderate width, not flattened, and rounded at the sides.
Length, *45 mm.

Habitat. — Holsteinborg Harbour, Greenland, 10 fath., "Valorous" Expedition,
1875 (A. M. N.); off Cape Frazer, 80 fath., Captain Feilden, in Nares' Arctic
Expedition (Gr. S. B.).

In dorsal outline C. groenlandica resembles most closely C sella $; but the lateral
aspect and style of surface sculpture is altogether different. In surface sculpture it
resembles C. affinis, but in lateral and dorsal aspects, and especially in the different
kind of tumidity of the shell and absence of flattened ventral surface, it is far
removed from that species. Lastly, as regards the lateral view, it assimilates
rather closely to C. concentrica, but the very peculiar dorsal form is different.

13. Cytherura nigrescens (Baird).

(Plate xix., figs. 1, 2.)

1868. Cytherura nigrescens, Brady, Mon. rec. Brit. Ostrac, p. 440, pi. xxxii., figs. 50-56 ; and pi. xxxix.,
%• 7.

1874. Cytherura nigrescens, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 192 ; pi. xi.,

figs. 28-32 ; and pi. xii., fig. 13.
1888. Cytherura nigrescens, Dahl, Die Cytheriden der Westlicli, Ostsee, p. 30, pi. iii., figs. 107-109 ;

pi. iv.,figs. 110-114.

This species is found all round the British shores, ranging from tide-marks
down to depths of at least 30 fathoms. It occurs also commonly in estuarine situa-
tions near the mouths of rivers, notably in those of Holland and the East Coast
of England, and we have found it also in freshwater dykes at Whittlesea.

Distribution. — Sars says that it is found everywhere living upon algae, near
the shore of Norway — a statement which we (A. M. N.) can fully confirm;
rivers Scheldt and Maas ; Holland (G. S. B.); Fosse de Cap Breton, Bay of
Biscay (A. M. N.).

Fossil. — Scotland, England, Ireland, Norway, and Canada.

14. Cytherura simplex, n. sp.
(Plate xviii., figs. 1, 2.)

1872. Cytherura simplex (name only), Brady and Robertson, Ann. and Mag. Nat. Hist., ser. rv., vol. xi.,
p. 66.

1874. Cytherura sarsii ("local variety"), idem, ibidem, vol. xiii., p. 117, pi. iv., figs. 6-7.

Shell of male(?), seen from the side, greatly elongated, siliquose, of nearly equal
height throughout, height to length as three to eight; anterior extremity well

of the North Atlantic and North -Western Europe.

201

rounded, without angularity above or below, greatest projection central ; posterior
extremity much narrower, not beaked, subtriangular, apex of triangle (t. e. ex-
tremity) central, obtuse, and rounded ; dorsal margin forming a much depressed
arch throughout, posterior declination rather steeper than the anterior ; ventral
margin slightly incurved throughout all its anterior portion, the sinuation closely
corresponding in arcuation with the dorsal margin, at one-fourth of the length
from behind an angularity is produced by the ventral margin here sweeping
upwards and backwards without curvature to the extremity. Seen from above,
the form is narrowly boat-shaped, the sides subparallel, the breadth less than the
height and equal to one-third only of length ; anterior extremity, or " bows," mode-
rately sharp ; posterior, or " stern," broadly rounded. Valves glassy and pellucid ;
the angulation of the ventral margin is made more evident from the fact that there
is here a minute plica just within the edge, which plica sometimes terminates in a
microscopic spine- point ; central areola very narrow, occupying a much smaller part
of the valves than in the allied species C. nigrescens, C.similis, and C. rudis, margined
by an opaque white line, its front edge commences dorsally at one-fourth of length
from anterior extremity, and passes downwards at first nearly transversely, then
bends suddenly with a flexuous wave obliquely backwards, the areola behind is
deeply and widely emarginate, so that its lower and posterior portion is tongue-
shaped ; from this tongue and from the front edging line numerous opaque hair-
like lines radiate through the substance of the shell. Length, *5 mm.

Habitat. — St. Ninian's Bay, Isle of Bute ; river Ouse ; Thames Estuary, 7 fath. ;
off St. Mary's, Scilly Islands, 10-12 fath. ; Birturbuy Bay, Ireland (G. S. B. and
D. R.) ; off Fairlie, Firth of Clyde (A. M. N.) ; Belfast Lough, Dr. Malcomson
(G. S. B.).

15. Cytherura concentrica, Brady, Crosskey, and Robertson.
(Plate xvii., figs. 28, 29 ; Plate xix., figs. 3, 4.)

1868. Cytherura concentrica (?), Norman, Last Eeport Dredging among the Shetland Isles, Brit. Assoc.

Eeport, p. 292 (name only).
1874. Cytherura concentrica, Brady, Crosskey, and Eobertson, Mon. Post-tert. Entom., p. 194, pi. xi.,

figs. 7, 8 ; and pi. xv., fig. 21.

Shell somewhat peach-stone shaped, highest in the middle, height equal to half
the length ; anterior extremity broadly and obliquely rounded, most produced
below the middle ; posterior extremity formed by the dorsal and ventral margins
equally and without angularity converging, and ultimately forming a short, obtuse,
central beak ; dorsal margin boldly arched, the arch more steep in front, where it

2 D 2

202 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

sweeps down almost to the infero-antcal rounded corner ; ventral margin slightly
sinuated in front of the middle. Seen from above, compressed, acuminate in front,
sharply and strongly mucronate behind ; width rather less than half the length.
Shell-surface concentrically striated round the sides of the valves, the central
portion of which is finely punctate or sculptured with little quadrangular or irre-
gularly-sided cells. This is the more general ornamentation of the fossil specimens.
In recent specimens the surface of mature shells is usually more smooth, sparingly
punctate, the anterior part of the shell with a few longitudinal striae, the posterior
sometimes exhibiting more or less traces of concentric striation. Immature shells
minutely punctate all over, the puncta running in lines which have a tendency to
concentric arrangement especially round the margins. Length of fossil specimens,
•6 mm. Length of recent specimens, '35 mm. Length of punctate young, '30 mm.

Some very small Cytherurce, with closely punctate surface — the punctation assum-
ing a concentric disposition round the margins — have been regarded by us as
the young of the present species, and vrere recorded by Dr. Norman in his Shet-
land Report. The same form has since been met with in several other places on
the British coast, and is figured in Plate x., figs. 28, 29. No unmistakable
C. concentrica, closely agreeing with the fossil types, have been found in our seas.
The small form must for the present be left in doubt.

We at present assume that these represent different conditions of our species,
and the two forms have been found together off Fairlie, in the Firth of Clyde, but
the larger recent specimens known to us are of somewhat less size than the fossil,
and the beak is not quite so much produced. The small specimens might have been
supposed to be the young of C. nigrescens, but we have not found intermediate
links ; while the difficulty is increased by another form known to us, and often
found in company with these punctate specimens, which differs slightly in outline,
and is devoid of the surface ornament ; and this latter form looks more like the
young of C. nigrescens.

British localities. — Among Laminariw, in 5-7 fath., Bressey Sound, Shetland ;
the Minch ; off Fairlie, Firth of Clyde ; Seaton Delaval, Northumberland ; Hartle-
pool; Robin Hood's Bay, Yorkshire; Salcombe, Devon (A. M. N.).

Distribution. — Lervig Bay, 10-25 fath.; off Batalden, near Floro ; Stoksund,
80-100 fath., Norway (A. M. N.) ; Gulf of St. Lawrence; off Spitzbergen ; off
Cape Frazer, 50-80 fathoms, Capt. Feilden, in Nares' Arctic Voyage ; and in lat.
73° 10' N., long. 53° 0' E. (G. S. B.).

Fossil. — Scotland.

of the North Atlantic and North-Western Europe.

203

16. Cytherura similis, Gr. 0. Sars.
(Plate xvin., figs. 7-9.)

1865. Cytherura similis, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 72, $ .
1868. Cytherura sarsii, Brady, Mon. rec. Brit Ostrac, p. 442 ; pi. xxxii., figs. 39-42, $ .
1870. Cytherura propinqua, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. v., p. 24,
pi. x., figs. 1, 2, $.

1874. Cytherura sarsii, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 197, pi. xi., figs.

24 27; pi. xiii, figs. 18, 19, $.
1874. Cytherura similis, idem, ibidem, p. 192 (partly, but not figures),* $ .

Female very like C. nigrescens, but larger, as well as differing in other par-
ticulars. Shell, seen from the side, subovate ; greatest height central, more than
equal to half the length; anterior extremity evenly rounded ; posterior extremity
with the beak very short, much less prominent than in C. nigrescens and obtusely
rounded ; dorsal margin boldly and evenly arched ; ventral slightly concave.
Seen from above, more tumid than C. nigrescens, ovate, width equalling half the length.
End-view ovate, tumid, widest towards the base, width and height equal. Surface
of valves smooth, or obscurely reticulated at the extremities, and rarely all over
the shell ; median areola in form as that of C. nigrescens, obtusely angulated in front,
and slightly emarginate behind. " Last joint of antennules very short, the three
preceding subequal in length to each other. Nail of the feet of moderate length.
Second joint of last foot equal to the combined length of the two following joints "
(Sars). Length, -55 mm.

Male. — Oblong, subquadrangular, of nearly equal height throughout, height
not equal to half the length. Outline as seen from above more compressed, long-
ovate, widest behind the middle, width considerably less than the height, sides
flattened in their central portion, gradually converging and acuminate in front,
much more rapidly converging and submucronate behind. End view broadly
ovate ; widest in the middle ; in other respects as the female. Length, 55
mm. ; of about the same length, but less high than female.

Habitat. — Oyster-ooze, Stranraer ; Dublin Bay, 3—4 fath. ; Rothesay Bay,
10-12 fath. (G. S. B. & D. R.), off the Mumbles, 2-3 fath. (G. S. B.). ; off Fairlie,
Firth of Clyde ; off Skipness, Loch Fyne, 40 fath. ; Seaton-Delaval, Northumber-
land, tide-marks (A. M. N.).

Distribution. — Very rare, Langesund, Norway ; Oxfiord, Finmark(G. O. Sars);
Drbbak, 120 fath.; Haakelsund, Kors Fiord, Norway, 3-10 fath. (A. M. N.);
Smith Sound, lat. 78° 57' N., Capt. Feilden in Nares' Arctic Voyage (G. S. B.).

Fossil. — Post-tertiary: Scotland, Ireland; Norway.

* See under Cytherura rudis and C. atra.

204 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

17. Cytherura rudis, Brady.
(Plate xviil, figs. 10-12; Plate xix, fig. 21.)

18G8. Cytherura rudis, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol.ii., p. 34, pi. v., figs. 15-17.
1871. Cytherura granulosa, Brady and Crosskey, Ostracoda from Post-tert. deposits of Canada and New

England, Geological Magazine, vol. viii., p. 5, pi. ii., figs. 14, 15, S .
1871. Cytheritra cristata, idem, ibidem, p. 6, pi. ii., figs. 12, 13, $ .

1874. (?) Cytherura similis, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., pi. xii., fig. 16.

Shell of female, seen from the side, oval, greatest height central ; equal to more
than half the length, the height nearly equal throughout the greater part of the
length ; anterior extremity very broadly rounded, greatest protrusion below the
middle, the arcuation being long and bold ; posterior extremity much narrower,
somewhat exserted centrally, but not beaked, slopes above and below this narrowly
rounded centre, very slightly arched ; dorsal margin boldly arched at the extre-
mities, slightly flattened in the central third of its length ; ventral margin very
slightly sinuated centrally, and obtusely angled at the juncture with the upward
slope behind. Seen from above, with subparallel sides, width less than height,
sides suddenly converging behind, more gently in front. Surface of valves nearly
smooth, in some specimens, recent as well as fossil ; within the inferior border there
is a very slightly elevated crescentiform ridge, which is extended partly round the
posterior margin. Shell of male, seen from the side, elongated, elliptical, twice as
long as broad, of nearly equal height throughout ; anterior extremity very broadly
and evenly rounded, as in the female ; the greatest protrusion below the middle
posterior and ventral margins, as in the other sex ; dorsal margin nearly straight
throughout the greatest part of its length, and remarkably subparallel to the
ventral. Outline seen from above, subcuneiform, widest at the posterior extremity,
where the valves converge with steep declivity, and their lips protrude mucronately ;
sides flattened, very slightly converging forward throughout the greater part of
their length, but ultimately more suddenly, the extremity being narrow, but blunt.
Length of male, "525 mm. ; of female, "5 mm.

The granulose appearance of the surface is characteristic of old and somewhat
worn shells, but not of living examples.

The specimen here figured and described represents the adult, but not aged
shell. In some specimens the crescentic ridge figured in the type of C. cristata,
Brady, is present ; in others scarcely a trace of it can be seen. The tyjDe of C. rudis,
Brady, is an aged specimen, in which the shell is much thickened, the crescentic
ridge strong, and the surface sculptured with large cells, which are for the most
part quadrangular, and also some transverse riblets, and this specimen is abnormal

of the North Atlantic and North-Western Europe.

205

in having the posterior extremity more produced and rostrate than usual ; but
on the same mounting are others which are exactly in form as the typical
C. cristata, and the surface sculptured, though less coarsely, as in the typical C. rudis.
We are disposed to refer to this species, also the ostracod which is figured on Plate
xil, fig. 16 of the Monograph of the Post-tertiary Entomostraca, as Cytherura (similis ?),
from the deposit at Loch Gilp ; though in the recent specimens which have come
under our notice we have not observed similar strongly pronounced longitudinal
riblets.

Great difference of sculpture is similarly found to prevail in the female of
C. sella, where hardty two specimens can be found alike, since sometimes it has a
quite smooth surface, at others very elaborate and varied ornamentation.

We cannot doubt that the above characterized forms are sexes of one species ;
both in fossil and recent state they have been found together, and the differences
are of similar character to those to be observed in the sexes of other species of
Cytherura.

Habitat. — Godhavn Harbour, Greenland, 5—25 fath., "Valorous" Expedition,
1875 (A. M. N.); Ginevra Bay, Spitzbergen, Mr. Lamont ; Smith Sound, 78° 37' N.,
210 fath., Captain Feilden, in Nares' Arctic Expedition (G. S. B.).

Fossil. — In Post-tertiary deposits at Portland, Co. Maine (Brady and Crosskey) ;
Scotland (Loch Gilp) ?.

18. Cytherura fulva, Brady and Robertson.
(Plate xix., figs. 9—11.)

1874. Cytherura fulva, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. xiii., p. 116,
pi. iv., figs. 1-5.

Shell of the female very tumid ; seen laterally subquadrate, broadly rounded in
front, produced behind into an obscure rounded subcentral beak ; superior margin
evenly and very slightly rounded, sloping steeply backwards towards the posterior
extremity ; inferior nearly straight, sinuated in front of the middle ; greatest height
situated in the middle and equal to rather more than half the length. Seen from
below, the outline is very broadly ovate, widest in the middle, the width being
somewhat greater than the height ; anterior extremity broadly rounded, with a
distinct central mucro, posterior also broad, but tapering to a subacuminate central
point. Shell of the male, seen laterally, much more elongated, with nearly straight
dorsal and ventral margins, the height equal to scarcely half the length ; the out-
line, as seen from below, is also much more compressed. Surface of the shell
obscurely reticulated and dotted, marked also especially on the inferior surface
with faint longitudinal furrows. Length, "5 mm.

206 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Habitat. — C. fulva was dredged pretty abundantly on a bottom of hard granitic
sand, in a depth of 10—40 fath., off St. Mary's and St. Agnes (Scilly Islands), and
more recently in depths of 20 and 30 fath., off the Durham Coast ; Dungeness
Bay, 7 fath. ; Fowey Harbour, 3 and 4 fath. ; off the Eddystone Lighthouse ; in the
river Ouse ; between tide-marks at Boulmer, Northumberland, Clifden Bay,
Ireland (G. S. B.); LochFyne; Stromness Bay; and Greenock (D. R); Firth of
Clyde; Salcombe, Devon; Westport Bay, and Valentia, Ireland; Seaton Sluice,
Northumberland, between tide-marks (A. M. N.) Irish Channel and Belfast Lough
(Malcomson).

Distribution. — Fosse de Cap Breton, Bay of Biscay, 30—60 fath. (A. M. N.) ;
rivers Maas and Scheldt (G. S. B.).

19. Cytherura clathrata, G. O. Sars.

1868. Cytherura clathrata, Brady, Mori. rec. Brit. Ostrac, p. 446, pi. xxix., figs. 43-46.
1874. Cytherura clathrata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 201, pi. xi.,
figs. 1-4.

Additional localities. — Boness, Firth of Forth ; coasts of Durham, Northumber-
land, and North Yorkshire ; between tide-marks at Whitley and Seaton Sluice,
Northumberland; river Ouse, at Lynn (G. S. B. and D. R); ten miles E. of
Balta, Shetland, in 72 fath. ; the Minch (A.M.N.) ; Irish Channel ; Belfast Lough;
and Island Magee, N.E. Ireland (Malcomson).

Distribution. — Lofoten Islands, 6-12 fath. (G. O. Sars) ; " Valorous" Expedition,
Stat. 3, Davis Strait, lat. 69° 31' N., long. 56° 1' W., 100 fath. (A. M. N.) ; Deevie
Bay and Ginevra Bay, Spitzbergen, Mr. Lamont ; off Cape Victoria, Bache Island,
Capt. Feilden in Nares' Expedition ; Hunde Islands, Baffin's Bay, 60-70 fath., Dr.
Sutherland's dredgings ; Hammerfest Harbour (G. S. B.).

Fossil. — Scotland, England (Bridlington), Ireland (Portrush), Norway.

20. Cytherura cellulosa, Norman.

(Synonym : Cytherura nana, G. O. Sars.)

1868. Cytherura cellulosa, Brady, Mon. rec. Brit. Ostrac, p. 446, pi. xxix., figs. 47-50, 60.
1874. Cytherura cellulosa, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 200, pi. xi.,
figs. 5,6.

A common and very distinct little species, almost ubiquitous round the British
coasts, between tide-marks and in moderate depths of water, and commonly
reaching up into the mouths of rivers.

of the North Atlantic and North -Western Europe.

207

Distribution. — Christiania Fiord (G. 0. Sars) ; Batalden near Floro, off Sar
toro Bergen Fiord, Kors Fiord, Stoksund 120 fath. — all in Norway (A. M. N.) ;
river Scheldt, near Antwerp (G. S. B.) ; Fosse de Cap Breton, Bay of Biscay,
180-200 fath. ; Bay of Naples (A. M. N.)

Fossil. — Scotland, England, Wales, Ireland.

Genus X. — Cytheropteron, G. O. Sars.
[Type, Cytheropteron latissimum (Norman).]
1. Cytheropteron latissimum (Norman).
Synonym: Cytheropteron convexam, G. O. Sars (non Cy there convexa, Baird).

1868. Cytheropteron latissimum, Brady, Mon. rec. Brit. Ostrac, p. 448, pi. xxxiv., figs. 26-30.
1874. Cytheropteron latissimum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 202, pi.
viii., figs. 19-23.

1878. Cytheropteron latissimum, Brady, Ostracoda, Antwerp Crag., Trans. Zool. Soc, vol. x., p. 403,
pi. lxix., figs. 1 a-rf.

This species is found pretty plentifully on many parts of the British coasts,
from low-water mark downwards, very rarely between tide-marks. It is most
abundant and of finest growth on the northern and eastern coasts, dying out
apparently towards the south. We have no record of its occurrence in the Medi-
terranean or Bay of Biscay, and it is extremely rare on the southern and western
coasts of England and Ireland, though common in the west of Scotland. It was
not found in any of the " Challenger" dredgings either from the Atlantic or else-
where, but it occurs in material brought from the Arctic regions. The Scilly
Island habitat noted elsewhere (Brady and Robertson, on Ostracoda taken among
the Scilly Isles, Ann. and Mag. Nat. Hist., ser. iv., vol. xiii. (1874), p. 115) seems
to be an error.

Distribution. — Christiania Fiord, and thence to Finmark (G. O. Sars) ; Lervig
Bay, Norway, 3—25 fath. (A. M. N.); Iceland; river Scheldt, Holland; Spitz-
bergen and Baffin's Bay (G. S. B.).

Fossil. — Scotland, England (Bridlington), Norway, Canada.

TRANS. EOY. DUB. SOC. , N.S. VOL. IV., PART II.

208 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

2. Cytheropteron nodosum, Brady.

1868. Cytheropteron nodosum, Brady, Mon. rec. Brit. Ostrac, p. 448, pi. xxxiv., figs. 31-34.
1874. Cytheropteron nodosum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 203, pi. viii.,
figs. 12-15.

Additional localities. — Shetland ; Firths of Clyde and Forth ; Montrose Basin ;
river Wansbeck, Northumberland ; off coasts of Durham and North Yorkshire ;
off Lantern Hill, Ilfracombe, and Eddystone Lighthouse ; Dungeness Bay ; Scilly
Isles (G. S. B. and D. R.) ; off Tarbert, Loch Fyne, 25 fath. ; Dogger Bank ;
Salcombe, Devonshire (A. M. N.).

Distribution. — Off Sartoro, Bergen Fiord, 15—40 fath. ; Lervig Bay, 3—25 fath. ;
Hardanger Fiord, off Stordoen, 50-100 fath. ; Fosse de Cap Breton, Bay of
Biscay, 180-200 fath. (A. M. N.) ; Gulf of St. Lawrence (G. S. B. and D. R.).

Fossil. — Scotland, England, Ireland, Canada, and Norway.

3. Cytheropteron pyra?nidale, Brady.
(Plate xx., figs. 1-3.)

1868. Cytheropteron pyrctmidale, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ii., p. 34, pi. v., figs.
11-14.

Shell tumid, subpyramidal ; seen from the side, subrhomboidal, highest in the
middle ; greatest height equal to more than half the length ; anterior extremity
obliquely rounded, posterior narrowed and produced in the middle ; superior
margin very strongly arched, highest in the middle, and sloping steeply towards
each extremity ; inferior slightly convex, sinuated in front and bending upwards
behind. Outline, as seen from above, obovate, widest about the middle, suddenly
and sharply acuminate in front, broadly mucronate behind ; width and height
about equal. End view triangular, sides very slightly convex. Shell-surface
marked with conspicuous fossae, which are arranged in transverse curved rows ;
ventral surface sculptured with interrupted longitudinal furrows. Length, '54
mm.

This species partakes of the characters of C. latissimun and C. punctatnm ; but
from the first-named species differs in the proportions and shape of the shell, and
from the latter in the style of surface-sculpture.

Distribution. — The type specimens were dredged by Messrs. Robertson and
Crosskey, in 25-30 fath., muddy bottom at Drobak, Christiania Fiord. Davis
Strait, lat. 69° 31' N., long. 56° 1' W., 100 fath., "Valorous," 1875 (A. M. N.);

of the North Atlantic and North -Western Europe.

209

Lincoln's Bay, Grinnell Sound 82° 8' N., Tyndall Glacier 27 fath., off Cape
Frazer 50 and 80 fath., Captain Feilden in Nares' Arctic Expedition; Deevie and
Ginevra Bays, Spitzbergen, Mr. Lamont (G. S. B.).

The specimens taken off the Lantern Hill, Ilfracombe, and referred to this
species, we now look upon as belonging to C. nodosum.

4. Cytheropteron inflation , Brady, Crosskey, and Robertson.
(Plate xx., figs 19-21.)

1868. Cytheropteron inflatum (B., C, and E.), Brady, Contrib. to Study of Entomostraca, Ann. and

Mag. Nat. Hist., ser. nr., vol. ii., p. 33, pi. v., figs. 8-10.
1874. Cytheropteron inflatum, Brady, Crosskey, and Robertson, Post-tertiary Entom., p. 204, pi. viii.,

figs. 24-27 ; pi. xiv., figs. 26-29.

Shell, seen laterally, subrhomboidal or subtriangular, greatest height in the
middle, and equal to two-thirds of the length ; anterior extremity rounded, pos-
terior produced into a wide, obtuse, median beak ; superior margin very strongly
arched, gibbous, highest in the middle ; inferior convex in the middle in the situa-
tion of the lateral ala. Seen from above, the outline is broadly ovate, with equally
tapering and sharply mucronate extremities ; greatest width situated in the middle,
and equal to more than half the length. End view almost quadrate, scarcely at
all tapered at the apex. Surface of the shell minutely and closely punctate ; lon-
gitudinally striated on the ventral surface, alseform processes evenly and boldly
rounded, and but slightly prominent. Length, *65 mm.

British Habitat. — Loch Fyne (A. M. N.).

Distribution. — Stoksund, near mouth of Hardanger Fiord, 126 fath., Norway
(A. M. N.); Ginevra Bay, Spitzbergen, Mr. Lamont; Cumberland Inlet, Baffin's
Bay, 15± fath. ; and North Atlantic (G. S. B. and D. R.).

Fossil. — Scotland, Canada.

5. Cytheropteron subcircinatum, G. O. Sars.

(Plate xx., figs. 26-28.)
1865. Cytheropteron subcircinatum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 81.

Shell, seen from the side, subovate, greatest height central, more than half the
length ; anterior extremity rather narrowly rounded, greatest projection nearly
central ; posterior extremity slightly produced into a short central beak, which is
broadly truncate at the end ; dorsal margin very boldly arched, anterior and pos-
terior declination of nearly equal length ; ventral margin slightly concave in front,

2 E 2

210 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

then overhung by the convexity of the lateral protuberance, behind which it slopes
upwards to the hinder extremity. Seen from above, the form is very broadly oval,
breadth greater than the height, and in Sars' type-specimen equal to two-thirds of
the length (in ours to somewhat less), broadly pointed in front, mucronate behind.
Valves having the lateral protuberance extending along the greater part of the
length, its greatest convexity central, thence towards both ends gradually sloping
away into the body of the valve without angularity ; surface pitted with small
round foveolae. Length, *50 mm.

This is not C. subcircinatum, Brady, Mon., which is the C. depressum of this
Paper. (See p. 218.)

Our Norwegian examples have been identified by Professor Sars, who has also
kindly sent to us a drawing of the type-specimen.

C. subcircinatum approaches to C. latissimum (Norman), from which, however, as
Sars pointed out in his description, it may at once be distinguished, " protuberantia
laterali fere semicirculariter arcuatet, minimeque angulata."

Habitat. — Christiania Fiord, Norway, very rare (Gr. 0. Sars) ; Lervig Bay,
Stordoen, Norway, 2-10 fath. (A. M. N.).

6. Cytheropteron Iceve, n. sp.
(Plate xx., figs. 29-31.)

Shell, seen from the side, nearly ovate, greatest height in front of the middle,
equal to two-thirds of the length ; anterior extremity remarkably broadly, and
evenly rounded throughout ; posterior extremity mucli narrower, the dorsal slope
anterior to it being long, evenly rounded; dorsal margin evenly arched (the
central portion in one of the valves slightly flattened), anterior slope very slight
and gradual, posterior much steeper ; ventral margin straight. The greatest
tumidity is, as usual in the genus, on the ventral portion of the posterior half, but
this tumidity is only effected by the gentle rising of the shell on all sides, and it as
well as all parts of the surface is smooth and devoid of sculpture. Seen from above,
the greatest tumidity is at about one-fourth the length from the posterior extremity,
behind which the sides rapidly and without convexity converge, while forwards
the approach to each other is gradual for some distance, until an angularity is
formed by their more rapid convergence to the anterior extremity, which is
narrower than the posterior. Length, -6 mm.

Two single valves, dredged by H. M. S. " Porcupine," Stat. 41, 1869, lat.
49° 4' N., long. 12° 22' W., in 584 fath. (A. M. N.).

of the North Atlantic and North -Western Europe.

211

7. Cytheropteron punctatum, Brady.

Synonym : Cytheropteron tricorne, Brady [non C. tricorne, Bornemann).

1868. Cijtheropteron punctatum, Brady, Mon. rec. Brit. Ostrac, p. 449, pi. xxxiv., figs. 45-48.

Additional localities. — Off Farland Point Cumbrae, amongst shell debris in
19 fath. ; Lochgoil, 30 fath. ; off Girvan, 12-15 fath., and other places in the Firth
of Clyde ; Westport and Roundstone Bays, Ireland ; off Penarth Head, and
Mumbles, South Wales (G. S. B. and D. R.); Shetland, 10 miles east of Island of
Balta, 75 fath. ; off Tarbert, Loch Fyne, 25 fath. (A. M. N.) ; Belfast Lough (Dr.
Malcomson ).

Distribution.— Oft Sartoro, Bergen Fiord, Norway, 15-40 fath ; Fosse de Cap
Breton, Bay of Biscay, 180-200 fath. (A. M. N.).

8. Cytheropteron intermedium, G. S. Brady.

1878. Cyteropteron intermedium, Brady, Ostracoda Antwerp Crag, Trans. Zool. Soc, vol. x., p. 403,
pi. lxix., figs. 3 a-c.

1880. Cytheropteron intermedium, Brady, Beport " Challenger " Ostracoda, p. 137, pi. xxxiv., figs.
1 a-d.

Shell elongated. Seen from the side, flexuous, subrhomboidal, depressed in
front, highest near the middle, height equal to more than half the length ; anterior
extremity obliquely rounded ; posterior produced above the middle into a small,
slender beak, below which it sweeps downwards with an oblique gentle curve ;
dorsal margin moderately arched ; ventral sinuated in front, convex behind the
middle. Seen from above, the outline is hastate, widest behind the middle where
the lateral alae project outwards at an obtuse angle; from this point the lateral
margins converge in a gentle curve towards the front, terminating in a produced
subacuminate extremity ; backwards the sides converge from the extremities of the
alae at first almost rectangularly, then more gradually to form the posterior ex-
tremity, which, like the anterior, is subacute. End view equilaterally triangular,
rounded at the apex ; lateral angles produced and truncated; sides gently obtusely
convex. Shell almost smooth ; ventral surface slightly nodulated and irregular.
Length, -5 mm.

Distribution. — Vigo Bay, Spain, 11 fath., "Challenger" Expedition (G. S. B.).
Fossil. — Crag ; Antwerp (G. S. B.).

212 Brady and Norman — Monograph of the Marine and Feshwater Ostracoda

9. Cytheropteron crassipinnatum, n. sp.

(Plate xx., figs. 16-18.)

Shell, seen from the side, subovate, highest in the middle, greatest height equal
to two-thirds of the length ; anterior extremity not broad, obliquely rounded,
greatest projection below the middle ; hinder extremity produced into a well-
developed, blunt beak ; dorsal margin boldly arched, posterior declination longer
than the anterior ; ventral margin slightly concave in front, then convex — the
convexity chiefly occasioned by the outline of part of the overhanging ala — behind
the margin slopes gradually upwards to form the beak. Seen from above, the form
is in front broadly triangular, the central portion of the base of the triangle pro-
duced behind into a very large central mucro formed by that portion of the shell
which is behind the alee, lateral angles almost rectangular but furnished with a
minute triangular outwardly-directed point, the sides tapering, with slight convexity
at first, to the rather blunt anterior extremity ; greatest width equal to about four-
fifths of the length. Valves solid, their surface sculptured with irregular cells, the
alae very solid and blunt at the edge ; on a line with and above the point whence
the ala springs behind there is a slight protuberance on the side of the shell.
Length, *40 mm.

In outline this species, whether seen dorsally or laterally, is very like the young
of C. alatum, but may be distinguished from it by the solidity and bluntness of the
edge of the ala?, and by the surface sculpture. The same characters distinguish
it from C. hamatum, and well-marked differences in the dorsal aspects separate it
from the last-named species, and also from C. punctatum, to which latter species it
approaches in the substantial character of the ala.

Dredged fifteen miles off Valentia, Ireland, in 1870 (A. M. N.).

10. Cytheropteron hamatum, G. 0. Sars.

(Plate xx., figs. 13-15.)

1868. Cytheropteron vespertilio, Brady, Ann. and Mag. Nat Hist., ser iv., vol. ii., p. 33, pi. v., figs. 6, 7

[non Cypridina vespertilio, Reuss).

1869. Cytheropteron hamatum, G. 0. Sars, Nye Dybvandscrustaceer fra Lofoten. Vidensk-Selsk Forhand,

p. 172.

Shell of female, seen from the side, shortly subovate, highest in the middle,
height equal to more than half the length ; anterior extremity obliquely rounded,

of the North Atlantic and North -Western Europe.

213

most prominent below the middle ; posterior extremity somewhat produced, form-
ing a short beak, which inclines upwards ; dorsal margin boldly arched, anterior
declination much steeper than posterior ; ventral margin slightly sinuated in front,
afterwards convex ; lateral ala well developed, its edge acute, behind forming a
right angle with the shell, and furnished at its tip with an acute spine, which
is directed outwards, and generally curved forwards at its extremity. Seen from
above, very wide, the proportionate width in front being greater than in allied
species, nearly the greatest breadth is thus attained before the middle of the shell,
and thence the outline is continued with scarcely any additional expansion to the
alse ; behind the alse the valves are suddenly contracted ; both extremities are
acuminate, and the angle formed by the junction of the valves nearly equal;
greatest diameter equal to more than half the length. Surface of valves finely
punctate or pitted ; anterior extremity, in living examples, very finely toothed.
Length, "70 mm.

The Cypridina vespertilio, Reuss, to which Dr. Brady first referred this species is
scarcely this form, the hind margin of the alse showing remnants of teeth-like
points, such as are only known to us among recent species in C. alatum, which,
when actual comparison has been made, may prove to be Reuss's species.

Distribution. — Lofoten Islands, 120-300 fath. (G. 0. Sars) ; Stoksund, Hardanger
Fiord, Norway, 80-100 fath. (A. M. N.); Ginevra Bay, Spitzbergen, Mr. Lamont;
Cumberland Inlet, Davis Strait, lat. 66° 10' N., long. 65a 15' W., 15 fath. (Gr. S. B.)

Fossil. — Scotland (Dryleys and Elie).

11. Cyheropteron arcuatum, Brady, Crosskey, and Robertson.
(Plate, xx., figs. 28-30).

1874. Cytheropteron arcuatum, Brady, Crosskey and Robertson, Mon. Post-tert. Entom., p. 203, pi. viii.,
figs. 16-18 ; and pi. xiv., figs. 19-22.

Shell seen laterally very broadly subovate or subelliptical, highest in the middle,
height equal to nearly three-fourths of the length, broadly and evenly rounded
in front, behind produced very narrow, and scarcely rounded ; dorsal margin
forming an extremely bold arch, sloping gently towards the front, and very steeply
behind ; ventral sinuated in front of the middle, and upcurved behind. Seen from
above, the outline is arrow-headed or subhexagonal, width equal to two-thirds of
the length, the lateral margins, or ala?, in the middle of their course, almost straight
and parallel, the straight portions forming in front an obtuse angle at the point
where they converge in nearly straight lines to the acute anterior extremity, ending
behind in a rectangular truncation, from which projects in the middle the large

214 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

triangular posterior termination of the shell. End view triangular, equilateral,
the ventral line prominent in the middle, the upper angle tapering, acute, and
somewhat twisted. The valves are irregularly waved and sulcate in a transverse
direction, and just within the middle third of the ventral portion is a well developed
ala with rounded margin and rectangular posterior extremity. Length, "44 mm.

Habitat. — Dredged in 80 fath., Cape Frazer; Baffin's Bay. This species is
more like C. hamatum, Sars., than any other, but differs in its very strongly
arched outline, and in its rounder, wider, and less produced extremities. In the
few recent specimens which we have seen, the lateral alse are obtusely rounded, and
have no spine whatever; but in fossil specimens there is frequently a terminal spine.

Fossil. — Scotland and Ireland, post-tertiary.

12. Cytheropteron alatum, Gr. O. Sars.
(Plate xx., figs. 8-10.)

1865. Cytheropteron alatum, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 81.
1868. Cytheropteron alatum, Norman, Last Eeport Dredging among the Shetland Isles, Brit. Assoc.
Report, p. 294.

1872. Cytheropteron alatum, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. ix., p. 60, pi. ii., figs. 4-6.
1872. Cytheropteron inornatum, idem ibidem, p. 61, pi. ii., figs. 1-3.

Shell, seen from the side, long ovate, with very large and acutely-pointed lateral
alas, greatest height central, equal (exclusive of ala projection) to rather more
than half the length ; all the margins of the shell are very acute ; anterior extremity
well and evenly rounded ; posterior extremity produced centrally into a very large
rostrate process, obliquely truncate at the extremity ; dorsal margin very boldly
arched ; ventral sinuated in front of the middle, well arcuated behind ; lateral ala
seen prominently projected over the ventral margin, this alar process is of very
large size, with sharply acute edges, terminating outwardly in a sharp point, and
having the straight hinder margin edged with a series of about ten flattened plates,
of which the two innermost are usually larger than the rest. Seen from above,
the form presented is a very wide, acutely-angled triangle, the sides of which are
only very slightly convex, while the base consists of the dentated hinder edges of
the alae, between which the rostrate posterior portion of the shell is projected
(beyond the base of the triangle described) as a very acute triangular median
process ; width between the apices of the lateral alas greater than the length. End
view triangular, base greatly exceeding the height, sides slightly concave, basal
angles (ends of alas) excessively produced and acute. Surface of valves white,
pellucid, smooth or finely punctate. Length, -70 mm.

of the North Atlantic and North -Western Europe.

215

Half -grown examples differ considerably from the adult, and might easily be
confused with other species. This condition was described by Dr. Brady under the
name C. inornatum ; the shell is higher in proportion to its length, the alse much
less developed, and their hinder margin devoid of the flattened teeth. From
C. punctatum it is distinguished by the more delicate structure of the shell, the
acute margins, large alas, more produced beak, and smoother surface. See also
remarks under C. crassipinnatum.

Habitat. — Shetland, 5-8 miles east of the Island of Balta, in 40—50 fath. ; oft'
Tarbert, Loch Fyne, 25 fath. ; off Valentia, Ireland, 112 fath. (A. M. N.) In the
Clyde district it has occurred in Kilchattan, Fintry, and Rothesay Bays, Loch
Striven, and near Ardrossan (G. S. B. and D. R.).

Distribution. — Christiania Fiord, Norway in 20—30 faths. (G. 0. Sars !)

13. Cytheropteron mucronalatum, Brady.

1880. Cytheropteron mucronalatum, Brady, Eeport " Challenger " Ostracoda, p. 140, pi. xxxii., figs.
8a-d.

Shell, seen from the side, broadly subovate, or nearly semicircular ; height equal
to more than two-thirds of the length ; anterior extremity broadly rounded, and
bearing a few strong but short and blunt spines ; posterior narrower, also rounded
and furnished with a few spines, which are more acute than those of the front margin ;
dorsal margin very boldly arched, the arch continued down both ends of the shell to
the ventral margin, but the hinder slope is longer than the anterior ; ventral gently
convex. Seen from above, the outline is ovate, widest in the middle, width equal
to more than half the length, but not equal to the height ; sides converging gradually
towards the front, but more rapidly behind, both extremities running out in ob-
tusely mucronate form, with equal terminations. End view an acute-angled
triangle, the angles all well pronounced, sides longer than the base, and very
slightly convex ; base indented in the middle. Valves white, pellucid, or even
transparent and glassy, smooth ; close within, and overhanging aDd concealing the
ventral margin runs a much elevated crest, commencing (which is unusual in
the genus) at the anterior extremity of the shell, crowned by two linear riblets,
and gradually rising higher until it nearly reaches the hinder extremity, where it
abruptly terminates, and bears just before the termination a single, strong, but not
very long spine ; the valves attain their greatest tumidity at this crest, and more
especially on the hinder part of the shell, whence they rapidly converge, like the
sides of a high-pitched roof, to the dorsum, where their junction is very acute ; ven-
tral surface almost flat, but having a central longitudinal depression. The right

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. 2 F

216 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

and left valves are remarkably different in size and shape, the dorsal margin
of the right being abruptly truncated, and forming a perfectly straight line, very
much below the level of the valve of the left side, which is very boldly rounded.
Length, 1*3 mm.

Dredged by the " Challenger," near the Azores, Stat. 70., lat. 38° 25' N., long.
35° 50' W., 1650 fath. (Gh S. B.); and by the " Valorous" Expedition, 1875, in the
North Atlantic, Stat. 15, lat. 55° 58' N., long. 28° 42' W., 1485 fath.; and Stat. 16,
lat. 55° 10' N., long. 25° 58' W., 1785 fath. (A. M. N.).

In the Pacific it was dredged by the " Challenger" in from 1450 to 2050 fath.,
at five stations, ranging from off Japan to near the coast of Patagonia. This
remarkably fine species has thus probably a world-wide distribution in extreme
depths of the oceans.

14. Cytheropteron montrosiense, Brady, Crosskey, and Robertson.
(Plate xix., figs. 25, 26.)

1866. Cythere rhomboidea, Brady, New and imperfectly-known Ostracoda, Trans. Zool. Soc. Lond.,
vol. v., p. 381, pi. lxii., figs. 5 a-b (non C. rhomboidea, S. Fischer, 1854).

1868. Cytheropteron montrosiense (B., C, & B.), Brady, Ann. and Mag. Nat. Hist., ser. rv., vol. ii., p. 33,
pi. v., figs. 1-5 (figured, but not described).

1874. Cytheropteron montrosiense, Brady, Crosskey, and Bobertson, Mon. Post.-tert. Entom., p. 204,
pi. viii., figs. 28-36 ; and pi. xiv., figs. 13-16.

Shell of female (?), as seen from the side, subrhomboidal, nearly equal in
height throughout, height equal to more than half the length ; anterior margin
broadly rounded ; posterior obliquely truncate below, produced above into a broad
projection or beak; dorsal margin slightly convex, sinuated, or in old specimens
deeply sulcate behind just before its junction with the flattened beak; ventral
margin straight in front, convex behind. Outline, as seen from above, rhomboidal,
suddenly widened behind the middle ; extremities pointed, the posterior strongly
mucronate. End-view broadly triangular, the sides very convex ; the base flat,
and expanded at the sides. Surface of valves with the lateral protuberance or ala
very prominent, but short, forming a large irregularly rounded projection behind
the middle of the ventral margin, lateral surface pitted with large polygonal exca-
vations, ventral surface longitudinally rugose. Shell of the male (?) higher in
front, the dorsal margin sloping steeply backwards, lateral and posterior protu-
berances poorly developed ; surface markings smaller. Length, "55 mm.

British locality. — Roundstone Bay, Ireland (G. S. B. and D. R.).

Distribution. — Cumberland Inlet, in Baffin's Bay, 15 fath., lat. 66° 10' N., long.
67° 15' W. (G. S. B. and D. R.) ; Ginevra Bay, Spitzbergen, Mr. Lamont, lat. 82° 27'
N., 6 fath. ; Atlantic Ocean, 45 fathoms, Commander Dayman (G. S. B.).

of the North Atlantic and North -Western Europe.

217

Fossil. — Scotland, England (Hopton Cliff), Ireland (Woodburn), Norway.

The young of this species is described by the authors of the " Post-tertiary
Entomostraca," as having the valves glabrous, and devoid of all trace of pitted
sculpture.

15. Cytheropteron angulation, Brady and Robertson.

(Plate xtx., figs. 17, 18.)

1872. Cytheropteron angulatum, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv., vol. ix., p. 62,
pi. ii., figs. 7, 8.

1874. Cytheropteron angulatum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 206,
pi. viii., figs. 37-40.

Shell of female, viewed laterally, subrhomboidal, flexuous, bending slightly
downwards in front, and twisted much upwards behind, greatest height central,
equal to half or more than half the length ; anterior extremity broadly rounded ;
posterior without any infero-posteal angle, in that part sloping obliquely and
convexly backwards, and upwards, until at the supero-posteal angle a little upward-
bent lobe is produced ; dorsal margin boldly arched ; anteriorly the sweep is con-
tinued right round until the ventral margin is reached ; posteriorly there is a very
slight concavity in front of the pointed corner, where it joins the posterior margin ;
ventral margin straight or very gently convex in the middle, where, however, it is
hidden by the projection of the ala, the anterior portion convex, the posterior
arcuately sloping upwards. Seen from above, subpentagonal, somewhat boat-
shaped, widest in front of the middle ; sides in front of this rapidly converging at
an angle of fully 75° ; behind the outline consists of a series of sinuations, the
posterior extremity very wide, the corners jutting outwards, and termination
flexuous ; the greatest width is a little less than the height. Surface of valves flat-
tened, and, except at the alse, exceedingly rugged, the lateral ala not much elevated,
but having at some little distance within, and parallel to the margin, a strongly-
marked longitudinal ridge, below which is a groove, which is deepest behind,
and is crossed in front by a transverse bar which sometimes takes a nodulous
form ; above the ridge several irregularly flexuous ribs stretch transversely across
the valves to the dorsal margin, coalescing here and there into large rounded
eminences, and having in their interspaces numerous, irregularly angulated de-
pressions ; at the posterior extremity there is an elevated and lappet-like projec-
tion, having a curve upwards, and it is the presence of this lappet, which mainly
contributes to the very unusual aspect of this species. In two or three specimens
(? males) the lappet is absent, the appearance of the shell being thus considerably
altered. Length, -40 mm.

2 F 2

218 Brady and Norman — Monograph of the Marine and Freshivater Ostracoda

British localities. — Roscneath and Kilchattan Bay, 45—56 fath., Firth of Clyde;
Roundstone Bay, Ireland (G. S. B. and D. R.) ; Loch Fyne, off Tarbert, 25 fath.
(A. M. N.).

Fossil. — Scotland, England (Bridlington), Canada.

From its abundance in the glacial clays of Scotland it may be expected that
this species will hereafter prove to be a recent Arctic form.

16. Cytheropteron depressum, n. sp.
(Plate xx., figs. 22, 23.)

1868. Cytheropteron subcircinatum , Brady, Mon. rec. Brit. Ostrac, p. 447, pi. xxxiv., figs. 39-42 (but not
C. subcircinatum, G. 0. Sars, for which see p. 209).

The description of this species in the u Monograph," should be regarded as
inaccurate, as it was drawn up from Sars' description of the true C. subcircinatum,
in conjunction with the examination of the single British specimen then known of
the present species. In the Plate, what was regarded as the posterior extremity is
really the anterior.

Shell, seen from the side, subovate, greatest height equal to more than half the
length, and situated at the commencement of the posterior dorsal slope, the ventral
surface is remarkably broad and flat, the valves being projected directly outwards
and forming a sharp angle at the junction of the ventral and lateral margins,
anteriorly the true narrowly rounded margin is seen lying below and a little in
advance of the commencement of the gibbosity ; posterior extremity wider than
the anterior, rounded, its greatest projection central; dorsal margin flattened in its
central portion, posterior declination longer than the anterior; ventral margin
formed by two arcuations, the anterior of which occupies more than two-thirds of
the length, and is formed by the keeled edge of the protuberance, the posterior
commences at the point where the edge of the protuberance passes upwards, and is
formed by the true margin of the lips. The outline of the shell, seen dorsally, is a
broad oval, with boldly arched sides, greatest breadth exceeding the height, and
equal to more than two-thirds of the length ; extremities broad, the anterior
slightly the wider; from each valve, at its extremities, is projected a little
microscopic point. Valves glassy, subhyaline, with scattered opaque white specks.
Length, *35 mm.

Habitat. — Off North Yorkshire ; Scilly Islands ; off Eddystone Lighthouse ;
Westport, Clifden, Roundstone, and Galway Bays, and Lough Swilly, Ireland
(G. S. B. andD. R.); Dartmouth Harbour ; Valentia, Ireland (A. M. N.); Irish
Channel and Belfast Lough (Malcomson).

Distribution. — Rivers Scheldlrand Maas, Holland (G. S. B.).

of the North Atlantic and North -Western Europe.

219

17. Cytheropteron testudo, G. O. Sars.
(Plate xxi., figs. 1,2.)

1869. Cytheropteron testiulo, G. 0. Sars, Nye Dybvandscrustaceer fra Lofoten, Vidensk-Selsk. Forhand,
p. 29.

Shell, seen from the side, ovate, with a rostrate projection behind ; valves unequal,
the right higher and more strongly arched than the left ; greatest height central
much more than half the length, ventrally extremely broad and almost flat ; from
the basal edge the sides rapidly converge in a roof-like manner, so that dorsally
they are narrow and keeled at their junction ; anterior margin most prominent
below, thence sweeping with a continuous and almost semicircular curve round the
dorsal margin to the posterior extremity, where the dorsal and ventral margins
continued evenly backwards form a central narrow, sharp-pointed, horizontally
directed beak ; ventral margin itself hidden by the very acute edge of the lateral
protuberance, which is projected outwards, and presents an evenly convex outline.
Seen from above, very broadly oval, the greatest breadth central, much greater
than the height, and equal to two-thirds of the entire length ; sides boldly and
evenly arched ; front rounded, and remarkably obtuse, though not truncate (the
valves meeting at an angle of fully 150 degrees) ; behind the beak forms, beyond
the oval, a mucronate projection, which has a narrowly truncate termination.
Valves thin, pellucid, white, growing opaque and milky with age ; surface wholly
devoid of rugae, but covered with closely-set minute impressed punctations, and
bearing also a few scattered circular papillae ; ventral surface marked with rather
faint longitudinal ribs. Length, *5 mm.

Distribution. — Very rare in 120 fath., Lofoten Islands (G. 0. Sars); in two
places in the Hardanger Fiord, namely, off Stordoen, in 210 fath., and in
' Stoksund, 126 fath., and also off Batalden near Floro, Norway (A. M. N.).

18. Cytheropteron humile, n. sp.

(Plate xx., figs. 4-7.)

Shell extremely depressed ; seen from the side, the height is nearly the same
throughout and equal to only one-third of the length ; the extremities are obliquely
subtruncated, sloping very steeply from above, and only slightly rounded ; superior
margin straight, with a very slight sinuation in the middle ; inferior also
straight or but very slightly arcuate. Seen dorsally, the shape is broadly ovate,

220 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

with obscurely pointed, nearly equal extremities; the greatest width, situated in
the middle, is equal to more than two-thirds of the length, and twice the height ;
the ventral surface is almost perfectly flat, very faintly upturned at the ends, and
almost imperceptibly hollowed in the middle. Shell-surface finely and closely
punctate, and bearing also numerous rather large, flattened, circular papillae ; the
ventral surface has a few faint longitudinal lines in the centre, and round the
edges only bears a series of hair-like papillae. Length, *33 mm.

Several examples of this very distinct and interesting but minute species were
dredged in the Clyde, off Fort Matilda, Greenock, by Mr. Thomas Scott of that
place, to whose kindness we are indebted for the opportunity of describing it.
More recently we have received specimens from the Marquis de Folin, dredged
off Vigo (a. S. B.).

A most remarkable little species, on account of the excessive width as compared
with the height.

Genus XI. — Bythocythere, G. O. Sars.

[Type, Bythocythere turgida, G. O. Sars.]

1. Bythocythere constricta, G. 0. Sars.

1868. Bythocythere constricta, Brady, Mori. rec. Brit. Ostrac, p. 451, pi. xxxv., figs. 47-52.
1874. Bythocythere constricta, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 208, pi. xvi.,
figs. 9, 10.

1878. Bythocythere constricta, Brady, Ostracoda Antwerp Crag, Trans. Zool. Soc, vol. x., p. 405.

Additional localities. — Off north coast of Scotland ; off Roseneath and other
places in the Firth of Clyde ; Loch Long and Loch Fyne ; coasts of Durham and
North Yorkshire, 20-35 fath. ; off Lantern Hill, Ilfracombe ; off the Edd}^stone
and Mumbles, South Wales ; Scilly Islands ; Loughs Mulroy and Swilly, and
Dublin Bay, Ireland (G. S. B. and D. R.); thirty miles off Aberdeen; Scar-
borough, tide-marks; off Valentia, Ireland (A. M. N.); Irish Channel and Belfast
Lough (Malcomson).

Distribution. — A single specimen, 20—30 fath., Christiania Fiord, Norway
(G. O. Sars); off Sartoro, Bergen Fiord, 15—40 fath., and Kors Fiord, 180 fath.,
Norway; Fosse de Cap Breton, Bay of Biscay, 30—60 fath. (A. M. N.); Dee vie
Bay; Spitsbergen, Mr. Lamont (G. S. B.).

Fossil. — Crag ; Antwerp. Post-tertiary ; Scotland.

of the North Atlantic and North -Western Europe.

221

2. Bythocythere turgida, G. 0. Sars.

1868. Bythocythere turgida, Brady, Mori. rec. Brit. Ostrac, p. 452, pi. xxxiv., figs. 35-38.
1870. Bythocythere turgida, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. hi., p. 372,
pi. xiii., figs. 1-4.

Additional localities. — Off Eddystone Lighthouse ; Kilchattan, Roseneath and
Rothesay Bays, Firth of Clyde ; off Durham and North Yorkshire, 20—45
fath. ; among the Scilly Islands ; Roundstone Bay, Ireland (G. S. B. and D.R.);
St. Magnus Bay, and off the Island of Balta, Shetland, 50—73 fath. ; off Valentia,
Ireland (A. M. N.) ; Irish Channel and Belfast Lough (Malcomson).

Distribution. — Hollingspollen, near Drobak, Norway, 10—12 fath. (G. O.
Sars) ; Spitzbergen (?), Mr. Lamont ; Gulf of St. Lawrence, Mr. G. M. Dawson
(G. S. B.)

3. Bythocythere insiynis, G. O. Sars.

(Plate xxiii., figs. 1, 2.)

1869. Bythocythere insignis, G. 0. Sars, Nye Dybvandscrustaceer fra Lofoten (Vidensk-Selsk. Forhand,
p. 173).

Shell of male irregularly rugose and impressed, having two large nearly rec-
tangular lateral protuberances interrupted in the middle by a transverse furrow,
and behind irregularly crenulated. Seen from the side, the form is elongated sub-
rhomboidal, the greatest height scarcely equalling half the length ; dorsal margin
nearly straight ; ventral sinuated in the middle ; anterior extremity obtusely
rounded ; posterior obliquely truncate or exserted into an obtuse process, which is
continuous with the dorsal margin. Seen from above, subrhomboidal, greatest
width situated behind the middle, and more than half the length ; width gradually
decreasing in front, suddenly behind ; both extremities acuminate. Valves thin
and pellucid, sparingly furnished with short hairs. No eyes. Antennules very
slender, consisting of seven joints as in the other species, the last of moderate
length, slightly shorter than the preceding. Terminal portion of the copulatory
organs irregularly triangular, furnished with a single, short, apical seta. Length,
0-76 mm.

Habitat. — Very rare in 120 fath., Lofoten Islands (G. O. Sars).

Our figures are taken from a drawing kindly sent to us by the author.

222 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

4. Bythocythere bicristata, n. sp.
(Plate xix., figs 15, 16.)

The shell, seen laterally, is obliquely subquadrate, not much higher in front
than behind, the greatest height equalling about two-thirds of the length ; anterior
extremity oblique, moderately well rounded ; posterior subangular above, and
much rounded off below ; dorsal margin slightly gibbous at the anterior third and
sloping rather steeply in front, almost straight behind ; inferior slightly convex.
Seen from above, the outline is doubly triangular, the anterior two-thirds forming
a large triangle, from the posterior border of which projects a smaller one ; the
extremities obtuse, and the two large lateral protuberances rounded. End view
subquadrangular, the base very wide, convex, with sharply produced lateral angles,
the apex much narrower, and rounded at the angles ; lateral margins slightly con-
cave. The surface of the shell is smooth, or nearly so ; the lateral aspect of each
valve marked by a deep transverse median furrow, and dilated just within the
ventral margin, so as to form a prominent longitudinal ridge, which ends in an
abruptly rounded angle at the posterior third. Length, "65 mm.

This is a well-marked and very distinct species, the only examples of which
were dredged in the Unst Haaf, Shetland (A. M. N.).

5. Bythocythere recta (Brady).
(Plate xix., figs. 13, 14.)

1868. Cytheropteron rectum, Brady, Mon. rec. Brit. Ostrac, p. 476.

1869. Cytheropteron rectum, Brady and Robertson, Dredging West Ireland, Ann. and Mag. Nat. Hist.,

ser. rv., vol. iii., p. 372, pi. xx., figs. 6-8.
1874. Cytheropteron rectum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 206; pi. xiv.,
figs. 17, 18.

1886. Bythocythere pavo, Malcomson, Proc. Belfast Naturalists' Field Club, p. 261, pi. xxv., figs. 5-7

{junior).

Additional localities. — Westport Bay, Ireland, 4 fathoms (G. S. B. and D. R.) ;
St. Magnus' Bay, Shetland (A. M. N.) ; Belfast Lough and Irish Channel (Malcom-
son) ; Dungeness Bay (G. S. B.).

of the North Atlantic and North -Western Europe.

223

Distribution. — Fosse de Cap Breton, Bay of Biscay, 180-200 fath. (A. M. N.).
Fossil. — Scotland (Crofthead).

We have examined the types of Malcomson's Bythocythere pavo, and are satisfied
that it is the young of Bythocythere recta. It shows the commencement of the
future wing-like protuberance, as is slightly indicated in fig. 5 (Malcomson) ; and
the style of surface ornament is that of B. recta, which in this respect is unlike
any other Ostracod with which we are acquainted. We have met with it in several
localities.

6. Bythocythere dromedaria, G. 0. Sars.
(Plate xx., figs. 11, 12.)

1865. Bythocythere dromeclaria, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 86.

Shell of female, as seen from the side, ovate, greatest height situated in front
of the middle, and more than half the length ; evenly rounded in front, exserted
behind in the form of an obtuse process above the middle ; dorsal margin very
flexuous, forming a very prominent arch in front, then more deeply sinuated, and
as it were impressed ; ventral margin gently sinuated in front of the middle, and
behind this slightly arcuated. Seen from above, the form is broadly ovate, greatest
breadth central, and subequal to the height, lateral margin evenly arched ; both
extremities, but more especially the hinder, produced and acuminate. Valves thin
and pellucid, without any distinct structure, ornamented at both extremities with
some radiating lines near the margin. Colour, white. Last joints of the anten-
nules equal in length to the preceding. Second joint of the last feet shorter than
the combined length of the two following ; terminal nail very slender and almost
straight. Termination of the copulatory organs of the male short, subcordiform.
No eyes. Length of female, 0*80 mm.

Habitat. — Not common in 30—40 fath., Christiania Fiord, Norway (G. O.
Sars).

We are indebted to Prof. Gr. O. Sars for the type specimens from which our
figures are taken.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART IT.

2 G

224

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

7. Bythocythere simplex (Norman).
(Plate xxiii., fig. 9.)
Synonym : Bythocythere acuminata, Gr. O. Sars.

1868. Bythocythere simplex, Brady, Mon. rec. Brit. Ostrac, p. 450, pi. xxxiii., figs. 23-27 ; and pi. xl.,
fig. 8.

1874. Bythocythere simplex, Brady, Crosskey, and Robertson, Mon. Post-tert. Entoin., p. 308, pi. vii.,
figs. 20, 21.

Additional localities. — Many localities in the Firth of Clyde ; coasts of Durham
and North Yorkshire, common in depths of 20-45 fath. (G. S. B. and D. R.) ; St.
Magnus' Bay, and ten miles east of Balta, Shetland, 50-73 fath. (A.M/N.); Irish
Channel and Belfast Lough (Malcomson).

Distribution. — Dispersed on the Norwegian coast as far north as the Lofoten
Islands, in 12-30 fath. (G. O. Sars) ; Hunde Islands, Baffin's Bay, 60-70 fath.
Dr. Sutherland (Gr. S. B.).

Fossil. — Scotland, Ireland.

8. Bythocythere recurva, n. sp.
(Plate xix., figs. 24, 25.)

Shell thin and rather fragile. Seen from the side, subovate, with a rostrate
process behind ; greatest height anterior, equal to half the length, greatest com-
pression where the shell is highest, gradually becoming less high and more tumid
posteriorly, especially towards the ventral margin, a sharp keel surmounting the
most tumid part, and running parallel with and above the ventral margin, which
lies beneath ; anterior margin very widely and obtusely rounded ; posterior margin
exserted in the form of a beak which curves downwards, and the distal or posterior
margin of which is rounded ; a few bead-like tubercles stud the anterior and pos-
terior margins just within the borders; dorsal margin nearly straight; ventral
margin convex, especially in front. Surface of valves smooth and glassy. Seen
from above, subovate, greatest width behind the middle, extremities equally and
moderately acuminate. Length, *5 mm

A single valve of this very distinct form dredged in the Fosse de Cap
Breton, Bay of Biscay, 30-60 fath. (A. M. N.).

of the North Atlantic and North -Western Europe,

225

Genus XII. — Pseudocythere, G. O. Sars.
[Type, Pseudocythere caudata, G. 0. Sars.]
Pseudocy there caudata , G. 0. Sars.

1868. Pseudocythere ccmdata, Brady, Mori. rec. Brit. Ostrac, p. 453, pi. xxxiv., figs. 49-52 ; pi. xli., fig. 6.
1874. Pseudocythere caudata, Brady, Crosskey, and Robertson, Mon. Post-tert. Entoni., p. 210, pi. ii., fig. 9.
1880. Pseudocythere caudata, Brady, Report " Challenger " Ostracoda, p. 144, pi. i., figs. 6 a-d.

Additional localities. — Off north coast of Scotland ; Firths of Clyde and Forth ;
off Red Cliff, Yorkshire, 30 fath. ; off Eddystone Lighthouse; Scilly Islands;
Clifden, Westport, and Roundstone Bays and Mulroy Lough, Ireland (G. S. B. and
D. R.); Shetland; Isle of Skye; off Valentia, Ireland (A. M. N.) ; Irish Channel
and Belfast Lough (Malcomson).

Distribution. — Christiania Fiord, Norway, 30-40 fath. (G. O. Sars) ; Oster
Fiord, 50-100 fath. ; off Sartoro, Bergen Fiord, 15-40 fath. ; Hardanger Fiord,
25-200 fath., all in Norway ; Fosse de Cap Breton, Bay of Biscay, 180-200 fath. ;
off Isle of Capri, Bay of Naples, 40 fath. (A. M. N.) ; off Kerguelen Island, 20-120
fath. ; off Prince Edward's Island, 5.0-100 fath., and Stat. 323, lat. 35° 39' S., long.
50° 47' W., 1900 fath., " Challenger" (G. S. B.).

Fossil. — Scotland, Ireland.

Genus XIII. — Sclerochilus, G. O. Sars.
[Type, Sclerochilus contortus (Norman).]
Sclerochilus contortus (Norman).

1868. Sclerochilus contortus, Brady, Mon. rec. Brit. Ostrac, p. 455, pi. xxxiv., figs. 5-10 ; pi. xli., fig. 7.
1874. Sclerochilus contortus, Brady, Crosskey, and Robertson, Post-tert. Entom., p. 212, pi. x., figs.
33-35.

1880. Sclerochihis contortus, Brady, Report " Challenger " Ostrac, p. 147, pi. xxxiv., figs. 8 a, b.

Generally distributed in the British Seas; but rarely taken in abundance. It
sometimes occurs between tide-marks, but is more generally met with in deeper
water.

Distribution. — Rare, as far north as Finmark (G. O. Sars) ; Drobak, 120 fath. ;
off Sartoro, Bergen Fiord, 15-40 fath. ; Kors Fiord, 180 fath. ; Hardanger Fiord,
off Stordoen, 210 fath., and in Kloster Fiord, 40-80 fath., all in Norway;
Holsteinborg Harbour, Greenland ; and in Davis Strait, lat. 69° 31' N., long.
56= 1' W., 100 fath., " Valorous" Exped. ; Naples, shallow water (A. M. N.);
rivers Scheldt and Maas, Holland ; Spitzbergen, Mr. Lamont (G. S. B.).

Fossil. — Scotland, South Wales, Ireland, Norway, Canada.

2 G 2

226 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Genus XIV. — Cytherideis, T. R. Jones.

[Type, C. subulata, Brady. = Cythere Jlavida, Baird ; non Miiller.]

Shell slender, elongate, subovate, tapering and depressed towards the front, not
much compressed laterally. Hinge-margins nearly simple ; shell smooth, finely
punctate ; right valve overlapping the left in the centre of the ventral surface.
Antennules slender, sparingly setose ; last joint short, and bearing six short terminal
setae; penultimate and antepenultimate joints each bearing a single apical seta.
Mandible slender and curved, divided below into about four very small indistinct
teeth ; palp four -jointed, its first joint bearing on the inferior margin a conical
tooth-like process; third joint set along its entire length with a comb-like series of
straight equal setae. First segment of the maxillae much stouter and larger than
the rest. In other respects as in Cythere.

1. Cytherideis subulata, Brady.

1850. Cythere flavida, Baird, Brit. Entom.,p. 1G8, pi. xxi.,figs. 11, 12 a (non Miiller).
1856. Cytherideis flavida, Kupert Jones, Mon. Tert. Entom., England, p. 50, partim.
1868. Cytherideis subulata, Brady, Mon. rec. Brit. Ostrac, p. 454, pi. xxxv., figs. 43-46.
1872. Cytherideis subulata, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. rv., vol. ix., p. 55, pi. i.,
figs. 12, 13.

1874. Cytherideis subulata, var. fasciata, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. iv.»

vol. xiii., p. 117, pi. v., figs. 1-5.

1875. Cytherideis hilda, Brady and Robertson, On Dredging off tbe Durham and North Yorkshire

Coasts (Brit. Assoc. Report), p. 187.

1884. Cytherideis foveolata, Malcomson, Proc. Belfast Naturalists' Field Club, p. 261, pi. xxv., figs.

8-12.

1885. Cytherideis subulata, Carus, Prod. Faunae Mediterraneaa, p. 303.

Generally distributed round the British coasts, mostly in deep water, but occa-
sionally (as in the Island of Cumbrae) between tide-marks, and not unfrequently
also in tidal rivers.

Distribution. — Fosse de Cap Breton, Bay of Biscay, 30—60 fath. (A. M. N.);
Eastern Mediterranean, Port Said; CapeVerd Islands; Iceland (G. S. B.).
Fossil. — Crag (England).

This species varies a good deal in shape, size, and surface-markings. The
young shell is very regularly and delicately punctated, but the markings become
coarser, or are entirely obliterated with age. The form catalogued, but not de-
scribed, by Messrs. Brady and Robertson, under the name of C. hilda, seems to be
merely the young of C. subulata, while the variety C. fasciata is a large local variety

of the North Atlantic and North -Western Europe.

227

in which the punctured markings are almost absent, and which in the fresh state
is conspicuously banded with black, and has a delicate epidermic reticulation.
This form is about one-eighth longer than the typical C. subulata, and is less com-
pressed in front. The specimens dredged by Dr. Malcomson in the Irish Channel
and erroneously referred to C. foveolata, we consider to be the young of the present
species.

2. Cijtherideis foveolata, Brady.
(Plate xix., figs. 19, 20.)

1870. Cijtherideis foveolata, Brady, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 454, pi. xix.,
figs. 1-3.

Shell elongate, compressed ; seen from the side, siliquose, slightly depressed in
front ; greatest height situated about the middle, and equal to rather more than
one-third of the length ; extremities rounded, the anterior much the narrower ; dorsal
margin almost straight, ventral slightly sinuated in the middle. Seen from above,
elongate ovate, widest near the middle, tapering gradually towards the front, more
abruptly behind ; extremities acuminate ; width equal to about one-third of the
length. Shell-surface smooth, minutely and somewhat densely punctate, semi-
transparent, horny. Length, "80 mm.

Distribution. — Gulf of St. Lawrence, Mr. G. M. Dawson (G. S. B.) ; Davis Strait,
lat. 60° 55' N., lung. 55° 30', 57fath., " Valorous" Expedition, 1875 (A. M. N.).

C. foveolata is larger and more robust than C. subulata, and has the valves more
conspicuously and densely punctated. Instead of the form, as seen from above,
being cuneate, widest behind, and sharply acute in front, in C. foveolata, the greatest
breadth is central, and the anterior extremity much less acute. In the Greenland
specimens, moreover, the margins of the valves at the anterior extremity are den-
ticulated, and there are several concentric raised lines on the infero-anteal
portion of the valves.

Genus XV. — Cytherois, Willi. Miiller.

[Type, Cytherois fischeri (G. O. Sars) .]

Antennules long, six- jointed, sparingly setiferous, second joint very long.
Antennae 3—4 jointed, urticating seta very long, twice geniculated, poison-gland
small, last joint with a very strongly-developed terminal seta. Biting portion of
the mandible long and slender, without teeth ; palp long and slender, two- jointed,
beset about the last joint with bristles, branchial appendage rudimentary, consisting
of one long seta. Maxilla of the ordinary character, with one very much elongated

228 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

and geniculated segment. Mouth broader than usual, with coalescent upper and
under lip and rudimentary sucking disc. Shell structureless ; hingement of two
teeth on the right valve at the front and hinder end of the bar, and a median
overlapping edge on the left valve.

Cytherois fischeri (Gr. O. Sars).
(Plate xxi., figs. 20-22.)

1865. Paradoxostoma fischeri. G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 96.

1869. Sclerochilus (?) gracilis, Brady and Eobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. iii., p. 372,

pi. xx., figs. 11, 12.

1870. Paradoxostoma fischeri, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. iii., p. 362,

pi. xii., figs. 1-3.

1874. Paradoxostoma fischeri, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 215, pi. xvi.,
figs. 23, 24.

1884. Cytherois virens, Willi. Miiller, Archiv. fur Natugesch., p. 15, pi. ii., figs. 10-13.

1885. Paradoxostoma fischeri, Carus, Prod. Faunas Mediterraneae, p. 312.

1888. Paradoxostoma fischeri, Dahl, Die Cytheriden der Westlich. Ostsee., p. 34, pi. iv., figs. 115-126.

The shell, seen sideways, is sub triangular, highest in the middle, height equal
to less than half the length ; anterior extremity somewhat narrowed and obliquely
rounded, posterior broader and well rounded ; superior margin boldly and evenly
arched, inferior gently sinuated in the middle. Dorsal view elongated, subovate,
thrice as long as broad, broadest in the middle ; tapering towards the extremities,
which are pointed, the posterior rather the more obtuse. Shell-surface smooth
and polished, marked with irregularly disposed dendritic patches of black or dark
green. Length, '65 mm.

This species is so generally distributed round the British shores that it is
needless to specify localities ; its favourite haunts are amongst algae between tide-
marks and in the laminarian zone ; but it occurs also frequently in estuaries and
brackish water, as in the rivers and broads of the East Anglian fen district, and
has been found as far inland as Whittlesea. In such situations it is usually colour-
less, but when living amongst algae it is prettily maculated.

Distribution. — Christiania Fiord, shallow water (Gr. 0. Sars) ; Sylt, Pomerania
(Wilh. Miiller) ; Messina, Sicily (Seguenza).

Fossil. — Scotland, South Wales, Ireland.

of the North Atlantic and North-Western Europe.

229

Fam. V. — PARADOXOSTOMATIDiE.

Genus I. — Paradoxostoma, Fischer.
[Type, Paradoxostoma dispar, Fischer.]

1. Paradoxostoma variabile (Baird).

(Plate xxiii., fig. 10.)
1785 (?). Cythere flavida, Miiller, Entom., p. 66, pi. vii., figs. 5, 6.

1868. Paradoxostoma variabile, Brady, Mori. rec. Brit. Ostrac, p. 459, pi. xxxv., figs. 1-7, 12-17 ;
pi. xli., fig. 8.

1874. Paradoxostoma variabile, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entom., p. 213, pi x.,
figs. 29-32.

1888. Paradoxostoma variabile, Dahl, Die Cytheriden der Westlicli, Ostsee, pi. iv., figs. 127-136.

Generally distributed round the British Islands, between tide-marks and down
to about 20 fathoms' depth. Specimens taken amongst seaweeds between tide-
marks are usually richly maculated, while those from deep water are often nearly
or quite destitute of colour.

Distribution. — Found throughout the coasts of Norway (G.O.Sars and A.M.N.) ;
Holsteinborg Harbour, Greenland: "Valorous" Expedition (A. M. N.) ; Hunde
Islands, Baffin's Bay, 60-70 fath., Dr. Sutherland; and Davis Strait, lat. 67° 17'
N., long 62° 21' W., laminarian zone; rivers Scheldt and Maas, Holland; Spitz-
bergen, Mr. Lamont (G. S. B.).

Fossil. — Scotland, Ireland, Norway, Canada.

2. Paradoxostoma ensiforme, Brady.

1868. Paradoxostoma ensiforme, Brady, Mon. rec. Brit. Ostrac, p. 460, pi. xxxv., figs. 8-11.
1874. Paradoxostoma ensiforme, Brady, Crosskey, and Bobertson, Mon. Post-tert. Entpm., p. 215, pi. x.,
figs. 27, 28.

1878. Paradoxostoma ensiforme, Brady, Ostracoda Antwerp Crag, p. 406, pi. lxiv., fig. 2.

1880. Paradoxostoma ensiforme, Brady, Beport " Challenger " Ostrac, p. 150, pi. xxxv., figs. 3 a-d.

1885. Paradoxostoma ensiforme, Carus, Prod. Faunas Mediterranete, p. 312.

This species occurs commonly in the dredge off the coasts of Great Britain and
Ireland, and is perhaps quite as widely distributed as the preceding ; occurring
also, though not so frequently, between tide-marks.

Distribution. — Lervig Bay, Stordoen, Norway, 3-25 fath. ; Fosse de Cap
Breton, Bay of Biscay, 30-60 fath. ; shallow water, Naples, and off the Isle of

230 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Capri, 40 fath. (A. M. N.)j Vigo Bay, Spain, 11 fath., " Challenger" ; Piraeus;
Besika Bay ; rivers Scheldt and Maas, Holland (G. S. B.).

Fossil. — Crag: England, Antwerp. Post-tertiary : Scotland, England, South
Wales, Ireland.

3. Paradoxostoma abbreviatum, G. O. Sars.

1868. Paradoxostoma abbreviatum, Brady, Mon. rec. Brit. Ostrac, p. 458, pi. xxxv., figs. 22-25.
1874. Paradoxostoma abbreviatum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 214.
1880. Paradoxostoma abbreviatum, Brady, Report "Challenger" Ostrac, p. 150, pi. xxxv., figs.
1 a-d.

The distribution of this species, like the last, is general round the British
coasts, but it is less numerically abundant, and not so often met with between
tide-marks.

Distribution. — Rare ; Christiania Fiord, Norway, in laminarian zone (G. 0.
Sars) ; Batalden, near Floro, 200 fath. ; and Stoksund, in the Hardanger Fiord,.
80-100 fath. ; Lervig Bay, 3-25 fath. ; Lungegaards-vandet, Bergen ; Haakelsund,
Kors Fiord, all in Norway; Fosse de Cap Breton, Bay of Biscay, 180-200 fath.
(A. M. N.); river Scheldt, Holland; also Balfour Bay, Kerguelen Island, 20-50
fath., "Challenger" (G. S. B.).

Fossil. — Scotland, South Wales.

4. Paradoxostoma obliqitum, G. O. Sars.

1868. Paradoxostoma obliquum, Brady, Mon. rec. Brit. Ostrac, p. 459, pi. xxxv., figs. 18-21.

Additional localities. — Lamlash Bay and Cumbrae, Firth of Clyde ; Northum-
berland coast, between tide-marks ; off Lantern Hill, Ilfracombe ; the Mumbles,
South Wales ; Scilly Islands ; Clifden and Westport Bays, Mulroy Lough, and
Lough Swilly, Ireland (G. S. B. and D. R.); Robin Hood's Bay, Yorkshire, tide-
marks; Mylor Creek, Falmouth; Valentia Harbour, Ireland (A. M. N.) ; Irish
Channel and Belfast Lough (Malcomson).

Distribution. — Oxfiord, Finmark, very rare (G. O. Sars).

of the North Atlantic and North -Western Europe.

231

5. Paradoxosioma normani, Brady.

1868. Paradoxosioma normani, Brady, Mon. rec. Brit. Ostrac, p. 458, pi. xxxv., figs. 39, 40.
1886. Paradoxosioma truncation, Malcomson, Proc. Belfast Naturalists' Field Club, p. 262, pi. xxv.,
figs. 3, 4.

1886. Sclerochilus contortus, var. abbreviatus, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser iv.,
vol. iii., p. 372, pi. xx., figs. 15, 16.

Additional localities. — Montrose Basin ; Seaton Sluice and Budle Bay, Northumber-
land ; off the Durham coast, 10—20 fath. ; off Robin Hood's Bay, Yorkshire, 30 fath. ;
Dungeness Bay; among the Scilly Isles; and in Westport and Roundstone Bays,
and Lough Swilly, Ireland (G. S. B. and D. R.) ; among laminariae, Bressay Sound,
and St. Magnus' Bay, also 5-8 miles east of Balta, Shetland, 5-50 fath., living;
Whitby, Yorkshire, 5 fath. ; Dartmouth Harbour (A. M. N.); Irish Channel, and
Rockport, Co. Down (Malcomson).

Distribution. — Fosse de Cap Breton, Bay of Biscay, 180-200 fath. (A. M. N.).

Having examined specimens of Mr. Malcomson's P. truncatum, we are satisfied
that it is only a form of the present species. In the specimens with which he
favoured us before his lamented death, there is no such decided angle at the
infero-anteal corner as is represented in his figure 3, that angle being much more
rounded off.

6. Paradoxosioma pulchellum, G. O. Sars.

(Plate xxi., figs. 29, 30.)

1868. Paradoxostoma pulchellum, Brady, Mon. rec. Brit. Ostrac, p. 459, pi. xxxv., figs. 41, 42.
1870. Paradoxostoma pulchellum, Brady and Robertson, Nat. Hist. Trans. Northumberland and Durham,
p. 363, pi. xii., figs. 4, 5.

Additional localities. — Loch Ryan ; Firth of Clyde ; Boulmer, Northumberland ;
Hartlepool, tide-marks ; Roundstone Bay and Mulroy Lough, Ireland (G. S. B.
and D. R.); Loch Carron; Arran, N.B. ; Falmouth (A. M. N.); Belfast Lough
(Malcomson).

Distribution. — Valid, Christiania Fiord, rare (G. O. Sars) ; Lervig Bay,
Stordoen, Norway (A. M. N.).

TKANS. ROY. DUB. SOC, N.S. VOL. IV., PAET. II;

2 H

232 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

7. Paradoxostoma hibernicum, Brady.
(Plate xxi., figs. 15-17.)

1868. Paradoxostoma hibernicum, Brady, Mori. rec. Brit. Ostrac, p. 460, pi. xxxv., figs. 35, 36 ; and
pi. xl., fig. 7.

1868. Paradoxostoma sarniense, idem, ibidem, p. 460, pi. xxxv., figs. 26-29, pi. xl., fig. 9.
1870. Paradoxostoma hibernicum, Brady and Bobertson, Nat. Hist. Trans. Northumberland and Durham,
vol. hi., p. 362, pi. xii., figs. 10, 11.

During the last twenty years, having had opportunities of seeing this species
from many localities, we have come to the conclusion that L. sarniense must be
united witli it.

The great flattening of the ventral margin, especially on the posterior half,
where it is much expanded, combined with the usual presence in it of fine trans-
verse opaque white lines are points which especially characterize this species,
though partially shared by P. flexuosum, as well as by the genus Machwrina.

Additional localities. — Firth of Clyde ; Budle Bay, Seaton Sluice, and Boulmer,
in Northumberland ; Durham coast, 20—30 fath. ; Scilly Islands ; Clifden, Birturbuy
and Westport Bays, and Lough Swilly, Ireland (G. S. B. and D. R.); Filey Brig,
Yorkshire; Clew Bay and Valentia Harbour, Ireland (A. M. N.); Rockport, Co.
Down (Malcomson).

8. Paradoxostoma vitreum, G. O. Sars.

(Plate xxi., figs. 27, 28.)

1865. Paradoxostoma vitreum, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 95.

Shell of female, seen from the side, elongated, subovate, higher behind than in
front ; greatest height behind the middle, and less than half the length ; anterior
extremity narrowly rounded, point of greatest projection central ; posterior
extremity broadly and obtusely rounded ; dorsal margin forming a depressed arch,
flattened centrally, front declination gentle, behind the middle moderately
arcuate, and at the hinder extremity descending nearly perpendicularly ; ventral
margin very slightly sinuated in the centre. Seen from above, the outline is nar-
rowly ovate, greatest breadth central, and less than the greatest height. " Shell of
the male much more elongated and narrower, nearly three times as long as high.
Antennules very long and very slender, second joint greatly elongated, three

of the North Atlantic and North-Western Europe.

233

following joints subequal to each other, their combined length about equal to that
of the second joint ; antennas moderately strong, the second joint larger than usual,
the last furnished with two nails of unequal length. Mandibles more robust than
usual, inferior extremity obtusely acuminate. First maxillse having three unequal
lobes. Feet having the two distal joints subequal. Extremity of the copulatory
organs of the male subtriangular, obtusely angulated in front, somewhat exserted
behind. Length of female, "51 mm. ; of male, *53 mm."

Habitat. — Balta Sound, Shetland, laminarian zone (A. M. N.).

Distribution. — Thorshaven, Faroe Islands, collected by Mr. E. C. Davison
(G. S. B.); rare in 6-12 fath. in the Christiania Fiord, and also at Langesund,
Norway, at the same depth (G. 0. Sars) ; Lervig Bay, Stordoen, Norway,
3-25 fath. (A. M. N.)

We are indebted to Professor G. O. Sars for types of this species, with which
our own have been compared. In the young the broad posterior extremity is not
so much developed, and at this age it approaches very closely to the young of
Cytherois fischeri, from which it differs in its very compressed form, and much less
concave ventral margin. The young of P. pulchellum also approaches this form,
but is higher in proportion to the length.

9. Paradoxostoma fasciatum, n. sp.
(Plate xxi., figs. 25, 26.)

Shell, seen laterally, elongated, subovate, somewhat depressed in front, greatest
height situated behind the middle, and equal to more than one-third of the length ;
anterior extremity rounded and somewhat flattened, posterior evenly rounded ;
dorsal margin forming a flattened arch, with one continuous curve from end to
end, but more convex behind ; ventral margin somewhat convex, faintly sinuated
near the middle. The outline, seen dorsally, is much compressed, fusiform, with
sharply-pointed extremities, five times as long as broad. Surface of the valves
smooth and polished, marked with a broad median black band ; edges, especially
those of the posterior and ventral portions, much compressed. Length, '84 mm.

Habitat. — Jersey (A. M. N.) ; Clew Bay, Co. Mayo, 2-4 fath. (G. S. B. and D. R.).

This species is extremely like P. vitreum, Sars, but is larger and much more
compressed, and both ventral and dorsal margins are more protuberant behind the
middle ; the black transverse band is also characteristic.

2 H 2

234 Beady and Norman — Monograph of the Marine and Freshwater Ostrocoda

10. Paradoxostoma arcuatum, Brady.
(Plate xxi., figs. 5, 6.)

1868. Paradoxostoma (?) arcuatum, Brady, Mori. rec. Brit. Ostrac, p. 461, pi. xxxv., figs. 37, 38.
1874. Paradoxostoma arcuatum, Brady, Crosskey, and Kobertson, Mori. Post-tert. Entom., p. 217.

A rare species, of which only a single specimen was known at the time of the
publication of Dr. Brady's Monograph. It has since been found in the following
localities, but is apparently everywhere very rare : — St. Magnus' Bay, Shetland ;
Dartmouth Harbour ; Roundstone Bay, Ireland (A. M. N.) ; Clifden Bay, Ireland ;
Granton (G. S. B. and D. R.).

Fossil. — Raised-beach, at Oban, Scotland.

11. Paradoxostoma orcadense, Brady and Robertson.

(Plate xxi., figs. 18, 19.)

1872. Paradoxostoma orcadense, Brady and Kobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. ix.,
p. 53, pi. i., figs. 5-7.

1874. Paradoxostoma cuneatum, Brady and Robertson, Ann. and Mag. Nat. Hist., ser. rv., vol. xiii.,
p. 117, pi. v., figs. 6, 7.

Carapace, as seen from the side, elongated, subreniform or subtriangular,
highest near the middle, lower in front than behind ; height equal to two-fifths of the
length ; extremities well rounded, the anterior being rather the narrower ; superior
margin sloping at first gently forwards almost in a right line from its highest point,
but well arched behind ; inferior sinuatedin the middle. Seen from above, ovato-
cuneate, widest near the posterior extremity ; width equal to nearly one-third of
the length, subacuminate in front, rounded behind. Animal unknown. Length,
•55 mm.

Habitat. — Stromness Bay, Orkney, sandy bottom ; White Bay, Cumbrae,
and off Glen Sannox, Arran ; dredged in New Grimsby Harbour, and off St.
Mary's, Scilly ; Berehaven, Ireland (G. S. B. and D. R.).

The Scilly specimens are smaller and rather more angular than the types,
and were at first supposed to be distinct (described as P. cuneatum), but further
examination leads us to conclude that they belong properly to P. orcadense.

Distribution. — Lervig Bay, Norway, a single specimen ; Fosse de Cap Breton,
Bay of Biscay, 180-200 fath. (A. M. N.).

of the North Atlantic and North -Western Europe.

235

12. Paradoxostoma hodgei, Brady.
(Plate xxi., figs. 7, 8.)

1870. Paradoxostoma hodaei, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. hi., p. 371,
pi. xii., figs. 12, 13.

Carapace, seen from the side, elongated, subreniform ; greatest height situated
in the middle, and not much exceeding one-third of the length ; extremities nar-
rowed and rounded, the posterior the narrower ; superior margin boldly and evenly
arched, inferior sinuated in the middle, behind the sinuation well arched, and
curving gently upwards towards the extremity. Seen dorsally, the outline is com-
pressed, linear-ovate, about five times as long as broad, widest in the middle, and
tapering gradually and equally to the extremities* which are subacutely pointed.
Shell smooth and polished, transparent, yellowish. Length, '65 mm.

Dredged off the Durham coast ; off Callum's Bay, Bute, and in Lough Swilly,
Ireland (G. S. B. and D. R.); off Tarbert, Loch Fyne, 25 fath. (A. M. N.).

13. Paradoxostoma rostratum, G. 0. Sars.
(Plate xxin., figs. 3, 4.)
1865. Paradoxostoma rostratum, G. 0. Sars, Oversigt af Norges marine Ostracoder, p. 97.

Shell, seen from the side, elongated, narrowly subelliptical, greatest height
nearly central, much less than half the length ; anterior extremity very narrow,
obtusely pointed, and slightly curved downwards ; posterior extremity obtusely
rounded ; dorsal margin evenly arcuate ; ventral margin perfectly straight through-
out its entire length. Seen from above, the outline is nearly equally broad in front
and behind ; lateral margins nearly straight, and subparallel in the middle, greatest
breadth rather less than the height, both extremities acuminate. Valves thin,
smooth, horny ; their ventral margin moderately thickened, and laterally more
emarginate than usual towards the front ; dorsal margin of the left valve slightly
prominent in the middle. Anterior extremity of the valves protected by a rounded
concave laminar process. Animal unknown. Length, *74 mm.

Habitat. — Very rare at Oxfiord, Finmark (G. O. Sars).

The foregoing is Sars' description of the species, and the illustration we are
enabled to give is from an outline drawing, which he has most kindly sent to us.

236 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

14. Paradoxostoma productum, n. sp.

(Plate xxi., figs. 9, 10.)

Shell of male (?), seen from the side, siliquose, much curved, greatest height
behind the middle, about equal to one-third of the length ; anterior margin most
produced above the middle, to which point the dorsal margin evenly and arcuately
slopes, below this point of furthest projection the margin slopes obliquely ; pos-
terior margin much exserted, the sides sloping above and below to a central
narrowly-produced rounded point ; dorsal margin well and evenly arched
throughout, in front right down to the extremity, behind extended nearly hori-
zontall}T at the pointed termination ; ventral margin in front of the middle deeply
concave, behind the middle boldly arched, the hinder half of the shell being
much higher than the anterior half. Seen from above, the outline is very narrow
and elongated, greatest width central, much less than the height, and not one-
fourth of the length ; sides evenly but lowly arched, extremities equally acuminate
and pointed. Valves white, perfectly smooth, and lustrous. Length, '55 mm.
Shell of female (?) smaller, of similar shape, but not quite so produced behind,
more tumid, greatest breadth equal to the height. Length, *40 mm.

Of the larger form, which we have called the male, we have only seen two
specimens, the smaller form was taken with it ; but in the other three localities the
latter only was found. A specimen of the smaller form, of which we have examined
the animal, appears to be a female ; but we have not been able to determine the
sex of the larger form.

As yet only found in Norway ; off Sartoro, in the Bergen Fiord, in 15—40
fath. ; Lervig Bay, Stordoen, 25 fath. ; and in two places in Stocksund, which is
near the mouth of the Hardanger Fiord, in 80-100, and in 126 fath. (A. M. N.).

15. Paradoxostoma flexuosum, Brady.

(Plate xxi., figs. 11, 12.)

1868. Paradoxostoma flexuosum, Brady, Mon. rec. Brit. Ostrac, p. 461, pi. xxxv., figs. 31-34.
1872. Paradoxostoma flexuosum , Brady and Robertson, Ann. and Mag. Nat. Hist. ser. nr., vol. ix., p. 55>
pi. i., figs. 8, 9.

1874. Paradoxostoma flexuosum, Brady, Crosskey, and Robertson, Mon. Post-tert. Entom., p. 216,

pi. xvi., figs. 19, 20.
1874. Paradoxostoma tenerum, iidem, ibidem, p. 217, pi. xvi., figs. 21,22.

The form described under the name Paradoxostoma tenerum, in the " Monograph
of the Post-tertiary Entomostraca," is probably only the female of P. flexuosum.

of the North Atlantic and North - Western Europe.

237

We have seen it in several dredgings associated with the latter species ; but never
having been fortunate enough to find any but empty shells, we are unable to speak
with absolute certainty in the matter. In the following list of localities / or t.
imply that the forms flexuosum or tenerum were observed : —

Additional localities. — North coast of Scotland ; Stromness ; Firths of Forth and
Clyde ; off the Durham and North Yorkshire coasts ; rivers Ouse and Humber ;
Scilly Isles; PenarthHead; Dungeness Bay ; Eddystone Lighthouse ; Birturbuy,
Clifden, Westport, and Roundstone Bays, and Loughs Swilly and Mulroy,
Ireland (G. S. B. and D. R.); Shetland, /. and t. ; Inverary, 25—40 fath., t. ; off
Skipness, Loch Fyne, /. ; Dartmouth Harbour, /. and t. ; Valentia Harbour,
Ireland,/, and t. (A. M. N.); Irish Channel and Belfast Lough,/. (Malcomson).

Distribution. — Rivers Scheldt and Maas, Holland (G. S. B.) ; Oster Fiord,
100-200 fath.,/.; off Sartoro, Bergen Fiord, 15-40 fath., /. ; Lervig Bay, Har-
danger Fiord, 3-25 fath., / and t.\ Drobak, in the Christiania Fiord, 30—100
fath; Fosse de Cap Breton, Bay of Biscay, 180-200 fath.; Davis Strait, lat.
69° 31' N., long. 56° 1' W. 100 fath., "Valorous" Exped. (A. M. N.).

This is an extremely variable species, differing in amount of arcuation of the
dorsal margin, and degree of sinuation of the ventral, and in the proportions of
height and length ; also in the narrower or broader extremities, and in the amount
of convexity ; but we have seen so many intermediate links that, different as the
forms at first sight appear, we are unable to recognise them as distinct species.

Genus II. — Mactlerina (/xct^atpa, a knife).

= Xiphichilus, Brady (name preoccupied among Pisces).

[Type, Machcerina tenuissima (Norman).]

Shell very thin and fragile, smooth, glassy, pellucid ; valves compressed, elongate,
pointed at both ends, nearly equal ; ventral margins much compressed, forming a
flattened, knife-like plate, which is widest behind the middle, and marked by
several opaque transverse hair-like lines. Outline, as seen from above, compressed,
tapering evenly from the middle to each extremity. Hinge simple. Limbs ex-
cessively long and slender. Antennules six- jointed and quite destitute of setse.
Antennae sparingly setiferous. Mandibles very long and slender, styliform,
palp (?) biarticulate, slender and terminating in two long setse. Abdomen pro-
duced into two long tapering processes, which are destitute of claws.

238 Beady and Norman — Monograph of the Marine and Freshwater Ostracoda

1. Machcerina tenuissima (Norman).

(Plate xxi., figs. 13, 14.)

1868. Bythocythere tenuissima, Norman, Last Report Dredging among the Shetland Isles, Brit. Assoc.
Report, p. 294.

1870. Xiphichilus tenuissima, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. hi., p. 369,
pi. xii., figs. 6-9 ; and pi. xiv., figs. 5-10.

Elongated, doubly fusiform, extremities equal and gradually attenuated to acute
points. Seen from the side, the outline is slender, flexuous, with very produced
mucronate extremities, four times as long as broad, the greatest height being near
the middle ; dorsal margin regularly arched ; ventral flexuous but slightly convex,
especially behind the middle, where the margins of the valves are much appressed
so as to form a sharp, knife-like flange. Dorsal view excessively compressed
and elongated, quite five times as long as broad, tapering equally from the
middle to the extremities, which are very acute and attenuated. Surface perfectly
smooth. Antennules excessively slender, having the first four joints of nearly
equal length, and about nine times as long as broad, the last two about one-third
the length of the preceding. Antennae having a single seta at the apex of
each joint, and one in the middle of the penultimate ; urticating seta long and
slender, triarticulate ; last leg having the second joint excessively long, the third
about one-fourth, and the last one-half of its length, claws long, slender, and
slightly curved. Length, 1*15 mm.

Dredged in St. Magnus' Bay, Shetland, 30-60 fath. ; off Fairlie, Firth of Clyde,
Roundstone Bay, Killary Bay, and off Valentia, Ireland (A. M. N.) ; off the Island
of Cumbrae ; Kilchattan Bay, Bute ; off Skelmorlie, Ayrshire ; off the Durham
coast, 15-30 fath. ; off Great Ormes Head (Gr. S. B. and D. R.) ; Belfast Lough
(Malcomson).

2. Machwrina amygdaloides (Brady).

(Plate xvii., figs. 20, 21.)

1870. Xiphichilus amygdaloides, Brady, Nat. Hist. Trans. Northumberland and Durham, vol. iii.,p. 370,
pi. xiii., figs. 8-10.

Shell, as seen from the side, oblong-oval, or almond-shaped, gently tapering to
the extremities, which are much narrowed, rounded, and nearly equal in height ;
superior margin gently and evenly arched, but slightly sinuated in front of the

of the North Atlantic and North -Western Europe.

239

middle ; ventral margin sinuated in the middle, behind which it pouts considerably ;
greatest height in the middle, and equal to rather more than one-third the length.
Seen from above, the outline is much compressed, rhomboidal, or doubly fusiform,
tapering equally from the middle, where it is widest, to the acutely-pointed
extremities ; greatest width scarcely equal to half the height, and to about one-
fifth of the length ; surface perfectly smooth, the transverse opaque lines of the
knife-like ventral margin very conspicuous when seen from below. Animal
unknown. Length, '55 mm.

One British specimen only known, found by Mr. D. Robertson among sand
dredged off Papa, Shetland.

Distribution. — Fosse de Cap Breton, Bay of Biscay, 180-200 fath., a single
specimen ; Bay of Naples, shallow water, three specimens (A. M. N.).

Although so few specimens have been found of this species, it would
seem to have a wide geographical range. One of the Naples specimens differs
from the others in being longer in proportion to the height, and in having the
posterior extremity extended centrally in a sort of rostrate process, with rounded
termination. This, perhaps, may prove to be the male.

TRANS. ROY. DUB. SOC, N.S. VOL. IV. PART II.

2 I

240 Beady and Norman — Monograph of the Marine and Freshivater Ostracoda

APPENDIX.

OSTRACODA OF THE FEENCH GOVERNMENT'S EXPEDITIONS IN THE
" TRAVAILLEUR " AND "TALISMAN."

During the progress of this work there have been kindly sent to us by our
friend the Marquis de Folin some Ostracoda which he has picked out from the
dredgings of the French Government Expeditions in the " Travailleur " and the
" Talisman." Some of these species are from dredgings which fall within the
limits of the present Paper ; others are from off the coast of Africa ; but all are
from such great depths that they may be expected hereafter to be found to have
a wide range over the bed of the North Atlantic. Under these circumstances we
have considered it best to notice them in an Appendix, more especially as the
greater number of the forms will be found described in preceding pages.

3. Bairdia subcircinata, Nobis (see p. 113).

1880. Bairdia fonnosa, Brady, Ostracoda of the " Challenger " Expedition, p. 52, pi. x., figs. la-e.
(Not B.formosa, Brady, Ann. and Mag. Nat. Hist., 1868.)

Dredged by the " Talisman," in a depth of 2200 metres, June 23rd, 1883, and
in 1918 metres, lat. 27° 31' N., long. 16° 27' W.

5. Bairdia victriz, Brady (see p. 115).

Well- characterised specimens were found in material dredged by the " Talis-
man " in 1918 metres, lat. 27° 31' N., long. 16° 27' W. ; in 2334 metres near the
" Arguin Bank;" and in 836 to 1350 metres off the west coast of Morocco.

8. Bairdia simplex, Brady.

1880. Bairdia simplex, Brady, Report "Challenger" Ostracoda, p. 51, pi. vii., figs. 1 a-d.

Shell, viewed laterally, oblong, subovate, nearly twice as long as high .
extremities rather narrow ; anterior much broader than the posterior, evenly

of the North Atlantic and North -Western Europe.

241

rounded ; dorsal margin arched, ventral straight, or slightly convex. The outline,
as seen from above, is compressed, ovate, about twice as long as broad, widest in
the middle, extremities subacuminate. End view broadly ovate, widest in the
middle, width equal to two-thirds of the height. Shell-surface smooth, with a
few scattered hairs. Length, l'3mm.

A single specimen only, from 4060 metres. It was procured in 1883, but
there is nothing further to show the habitat.

9. Bairdia abyssicola, Brady.
1880. Bairdia abyssicola, Brady, Keport " Challenger " Ostracoda, p. 52, pi. vii., figs. 4 a-c.

in

Shell, seen from the side, subrenif orm ; highest in the middle ; height equal to
about three-fifths of the length ; anterior extremity much compressed at the edge,
broadly rounded, and, as it were, bent downwards ; posterior rounded, somewhat
narrowed, and flattened, and produced below the middle ; dorsal margin
very boldly arched throughout; ventral sinuated in the middle. Seen from
above, the outline is narrowly ovate, compressed at the extremities, which are
acute. Surface of shell quite smooth and polished. Length, £> . 1*5 mill., $.
1-8 m.

The specimens above described exactly correspond with the figure
" Challenger" Report, 4 b, there called the right
valve, except that the dorsal sinuation near the
anterior extremity is either altogether absent, or
in other cases less pronounced, than is re-
presented in that figure. With these specimens
occur others, which we suppose to be males. In
these, while the general characters are preserved,
the height is much less in proportion to the
length, and the dorsal margin is straight in its
central portion; the general form, therefore, is
more elongated.

The leading character of the species is the marked compression of the shell
at the extremities. The left valve is much larger than the right, and overnangs
it dorsally, in a similar manner to that of Bythocypris bosquetiana. (See pi. xiv..
fig. 4.)

In " Talisman " dredging in 2200 metres, June 23, 1883.

f

Bairdia abyssicola, x 30.

2 12

242 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

10. Bairdia folini, Brady.

1886. Bairdia folini, Brady, Les Fonds de la Mer, vol. iv., p. 195, pi. xiv., figs. 4, 5.

Shell, viewed laterally, having the dorsal margin boldly arched in front,
terminating in a very broadly-rounded anterior margin, which has no angularity
either above or below, and the greatest projection of which is central; behind,
the dorsal curve continues downwards, until a narrow, well-rounded posterior
termination is formed, the whole of which termination lies below the central line
of the shell ; ventral margin straight, but with a slight symptom of sinuosity.
Greatest height central, subequal to half the length. Seen from above, the outline
is narrowly ovate, greatest breadth central,
equal to nearly half the length ; anterior
extremity subacute, posterior acute. Surface
of valves perfectly smooth and polished, with-
out hairs, and without spines. Length, 1*75 m.

Dredged by the " Talisman," August 24th,
1883, in 4060 metres.

In form this somewhat resembles B. abys-
sicola, but is very distinct ; the valves are sub-
equal, the left not being, as in that species, „ . „. , ,.

^ ' &' it- Bairdia folini, x 25.

much larger than the right, and overhanging

the latter dorsally ; the posterior extremity is narrower, the convexity is greater,
and the extremities have not the remarkable compression of B. ahjssicola.

11. Bairdia affinis, Brady.

1886. Bairdia affinis, Brady, Les Fonds de la Mer, vol. iv., p. 195, pi. xiv., figs. 6, 7.

Shell, seen from the side, subreniform, the left valve much larger than the
right, less sinuated in outline, and overlapping
at all points except in front; greatest height
situated in the middle, and equal to three-fifths
of the length ; anterior extremity broad, obli-
quely subtruncate, scarcely rounded ; posterior
narrow, not produced, rounded, and forming,
with the dorsum, one continuous, boldly- arcuate
curve ; inferior margin slightly sinuated in the
middle, and very gently upcurved behind.
Seen from above, the outline is compressed,
oval, widest in the middle, about twice and

a-half as long as broad, only slightly tapered towards the extremities,

Bairdia affinis, x 40.

which

of the North Atlantic and North -Western Europe. 243

are equal and subacute. Surface of the shell perfectly smooth. Length,
1*05 mm.

One specimen only of this species was found in a dredging made by the
" Talisman," on the 7th of July, 1883, in a depth of 1918 metres.

12. Bairdia hirsnta, Brady.

1880. Bairdia hirsuta, Brady, Ostracoda of the " Challenger " Expedition, p. 50, pi. viii., figs. 3 a-d.

Habitat. — Strait of Bocayna, between Lanzarote and Fuerteventura, Canary
Islands ; coast of Soudan, 932 metres, July 12th, and 2334 metres, July 15th, 1883 ;
west coast of Morocco, 836 metres, 17th June, 1883.

1. Macrocypris minna (Baird), (see p. 117).

In lat. 28° 35' N., long. 15° 36' W., 1238 metres ; lat. 32° 31' N., long. 12° 08' W.,
1350 metres; off west coast of Morocco, June, 1883, 636-1200 metres; and in
lat. 23° N., long. 19° 50' W., 932 metres.

2. Macrocypris angusta (G. O. Sars), (see p. 117).
In lat 23° N., long 19° 50' W., 932 metres.

3. Macrocypris siliqitosa, Brady (see p. 118).

Localities—West coast of Morocco, 630, 836, 1350 metres; in lat. 23° N., long.
19° 50' W., 932 metres; in lat. 20° N., 2333 metres ; lat. 32° 31' N., long. 12° 08'
W., 1350 metres.

Bythocypris bosquetiana (Brady), (see p. 120).

One specimen dredged near the Arguin Bank, lat. 20° N., 2333 metres ; others
in a depth of 932 metres, lat. 33° N., long. 19° 50' W.; and West coast of
Morocco, 836 to 1200 metres.

13. Cythere sulcifera, Brady (see p. 133).

Well-developed and characteristic specimens of this species were dredged by
the " Talisman," June 16th, 1883, lat. 32° 31' N., long. 12° 08' W., in 1315
metres; July 7th, 1883, lat. 27° 31' N., long. 16° 27' W., 1918 metres; and June
27th, 1883, east of the Canary Islands, 975 metres.

244

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

39. Cythere echinata, G. O. Sars (see p. 150).

Between "lamer des Gargattes " and the Azores; and 11th August, 1883,
2792 metres ; " Coast of Soudan," 932 metres; west coast of Morocco, 836 metres,
17th June, 1883 ; in lat. 25° 01' N., long. 19° 15' W, 2638 metres ; in lat. 28° 35' N.,
long. 15° 36' W., 1238 metres; and in other localities of which we have not full
particulars.

40. Cythere acanthoderma, Brady (see p. 151).
North of St. Michael, Azores, in 2295 metres.

41. Cythere die ty on, Brady (see p. 152).

North of St. Michael, Azores, 2995 metres, and 4000 metres ; between the Azores
and the Bay of Biscay, 5005 metres ; and between " la mer des Gargattes" and
the Azores.

50. Cythere emaciata, Brady (see p. 159).

An elongated variety of this species, in which the height is less than usual,
but of which only a single example occurred, was procured by the u Talisman "
in 2995 metres, to the north of St. Michael, Azores.

69. Cythere milne-edwardsii, n. sp.

Shell, viewed laterally, oblong; height nearly equal throughout, but greatest
quite in front in a line with the hinge joint, which is very prominent, and situated
in a very forward position ; anterior and posterior extremities obliquely truncate,
the obliquity only slight, in both instances the greatest projection is below;
all four corners completely rounded off ; dorsal
and ventral margins straight and parallel, the
ventral only slightly longer than the dorsal.
Surface of valves rugose, with depressed tubercles
and small blunt spines, none of which are conspicuous
above the rest by greater size ; two low and indis-
tinct riblets pass longitudinally and convergingly
along the middle portion of the shell, not reaching
the front, and roundly united in a loop-like
manner at a short distance from the posterior
extremity. Seen from above, the sides are gently
convex, converging rather abruptly in front and more gradually behind, and
everywhere showing an irregularly sinuous and dentated outline. Length, 1 mm.

Cythere milne-edwardsii, x 40.

of the North Atlantic and North-Western Europe.

245

Dredged by the "Talisman" off the west coast of Morocco, 836 to 1200
metres, and near the " Arguin Bank," Africa, lat. 20° N., July 15, 1883, in 2333
metres.

We have named this species after Professor Alphonse Milne-Edwards, under
whose direction the " Talisman" exploration was conducted.

70. Cythere scaberrima, Brady.
1886. Cythere scaberrima, Brady, Les Fonda de la Mer, vol. iv., p. 198, pi. xiv., figs. 10, 11.

Shell of peculiar shape ; height equal to nearly half the length ; dorsal margin
gently arched, ventral nearly straight ; anterior extremity widely and somewhat
obliquely rounded, greatest projection above the middle; posterior margin very
obliquely truncate, sloping backwards from above, and so projected below that the
ventral margin is much longer than the dorsal, and at the infero-posteal corner the
union of the ventral and posterior margins is projected backwards in beak-like
manner, with truncated apex. Seen from above, the outline (of the single valve) is
triangular, widest behind the middle, the anterior portion very much broken and
spinous, the posterior somewhat less so. Surface
of the shell very rugose ; across the centre of the
valves is a deep sinus, in front of and behind
which the surface rises in an umbonal manner,
while towards the dorsal margin these protube-
rances terminate in two much elevated, rugged
and acutely-pointed spikes ; the whole surface
of the valves, including the spikes, to their very
summit, is covered with spines, subequal in size?
though a few at the margins are somewhat
larger than the rest. In the interior of the
valves the margins of the extremities are widely outspread and thickened ; across
their centre runs a strong transverse bar, in front and behind which are two
deep sinuses, which are represented externally by their umbonal protuberances.
Length, 1*1 mm.

A single valve only, from a " Talisman" dredging, made on 7th August, 1883,
in 3535 metres.

Cythere scaberrima, x 40.

246 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

4. Xestoleberis margaritea, Brady (see p. 190).
1866. Cytheridea margaritea, Brady, Trans. Zool. Soc, vol. v., p. 870, pi. lviii., figs. 6 a-d.

The types of this species, being picked out of sponge-sand, were, of course,
merely empty, bleached shells. They agree,
however, very closely in shape with speci-
mens sent to us by the Marquis de Folin, which
were dredged off Muros, Galicia, and are also
all empty shells. But Dr. Norman's collection
contains specimens from the Bay of Naples
undoubtedly identical with those from Muros,
containing the soft parts of the animal, and
showing the natural coloration of the shell —
yellowish, with three dark transverse bands, or
blotches, on each valve.

We do not now consider the specimens called X. margaritea in the "Challenger"
Report to be rightly referred to that species. We give here drawings of the
Neapolitan form, and on re-examination of specimens from the several localities,
we no longer entertain the opinion expressed in the body of this memoir (p. 190)
as to the identity of X. intermedia with this species.

Xestoleberis margaritea, x 75.

2. Krithe prodncta, Brady (see p. 180).

Dredged by " Talisman," in 4060 metres ; locality not stated ; also lat. 25° 1' N.,
long. 19° 15' W., 2638 metres.

13. Cytheropteron mucronalatum, Brady (see p. 215.)
Between the Azores and the Bay of Biscay, 27th August, 1883, 5005 metres.

EXPLANATION OF PLATE XXXV.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART V.

PLATE

XXXV.

LETTERING ADOPTED IN ALL THE FIGURES.

a., . .

. acontia.

m.f., .

. mesenterial filament.

s. d.,

. sulcar directive mesentery

ax. t., .

. axial tentacle.

»., . .

. nucleus.

s. 1. en.,

sulco-lateral endoccele.

e. in., .

. circular muscle.

as., . .

sophagus.

si., . .

. sulculus.

c. m. en.,

. circular muscles of endo-

as. gr.,

. oesophageal groove.

si. d., .

. sulcular directive mesen-

derm.

ov., . .

. ovum.

tery.

cu., . .

. cuticle.

p. d., .

. pedal disk.

si. en., .

. sulcular endoccele.

d., . .

. directive mesenteries.

p. m., .

. parietal muscle.

si. ex., .

. sulcular exocoele.

ec, . .

. ectoderm.

r. m., .

. retractor muscle.

si. 1. en.,

. sulculo-lateral endoccele.

en., . ,

. endoderm.

sc., .

. sucker.

s. 1. m.,

. sulco-lateral mesentery.

g. s., .

. grains of sand.

s., . .

. sulcus.

si. 1. m.,

. sulculo-lateral mesentery.

1. ex., .

. lateral exoccole.

s. en., .

. sulcar endoccele.

sp., . .

. sperm-cell.

*»., .

. mesogloea.

8. ex., .

. sulcar exoccele.

z., . .

. zooxanthellse.

Figure.

Halcampa chrysanthfihm (Peach).

2

1. Transverse section through oesophageal region, x # = about 14 diam.

2

2. Transverse section through generative region of body, x ^ ^ .

Halcampa arenarea, Haddon.

3. Transverse section through oesophageal region, x 10 diam.

Chondractinia nodosa (Fabricius).

4. Vertical section through the body of a preserved specimen ; natural size.

Chondractinia digitata (0. F. Miiller).

5. Part of a transverse section through the oesophageal region (the spaces in the mesogloea

4

appear to be due to some imperfection in the method of preparation), x # .

4

6. Transverse section of a tertiary mesentery, x -j.

7. Vertical section through the specimen drawn in fig. 12, pi. xxxiii., x 2 diam.

Chitonactis marioni, n. sp.

8. Vertical section through upper portion of the body-wall, including the sphincter

musclC; _L_.

2

9. Transverse section through a mesentery, — .

Sormathia margarita, Gosse.

3

10. Vertical section through the circular muscle, x

a * 10

1 1 . Detail of muscle of previous figure.

3

12. Transverse section through body-wall and secondary mesentery, x — .

^2

Trans. R.Dub.S.,N.S., Vol. IV.

Plate XXXV.

EXPLANATION OF PLATE XXXVI.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART V.

PLATE

XXXVI.

LETTERING ADOPTED IN ALL THE FIGURES.

a., . .

. acontia.

m.f., .

. mesenterial filament.

8. d.,

. sulcar directive mesentery.

ax. t., .

. axial tentacle.

»., . .

. nucleus.

s. 1. en.,

. sulco-lateral endoccele.

cm., .

. circular muscle.

CCS., . .

. oesophagus.

si., . .

. sulculus.

c. m. en.,

. circular muscles of endo-

ess. gr.,

. oesophageal groove.

si. d., .

. sulcular directive mesen-

derm.

ov.t . .

. ovum.

tery.

cu., . .

. cuticle.

p. a., .

. pedal disk.

sl. en., .

. sulcular endocoele.

d.,

. directive mesenteries.

p. m., .

. parietal muscle.

si. ex., .

. sulcular exocoele.

ec, . .

. ectoderm.

r. m., .

. retractor muscle.

sl. 1. en.,

. sulculo-lateral endoccele.

en., .

. endoderm.

sc., . .

. sucker.

s. 1. m.,

. sulco-lateral mesentery.

ff.S., .

. grains of sand.

s., . .

. sulcus.

sl. 1. m.,

. sulculo-lateral mesentery.

1. ex., .

. lateral exocoele.

s. en., .

. sulcar endoccele.

sp., . .

. sperm-cell.

m., . .

. mesoglcea.

8. ex., .

. sulcar exocoele.

z., . .

. zooxanthelloe.

Figure.

Edwardsia tecta, n. sp.

2

1. Transverse section through the oesophageal region, — .

2. Transverse section through a mesentery, — .

Edwardsia timida, Quatrefages.

2

3. Transverse section through a mesentery, — .

Edwardsia beautempsii, Quatrefages.

2

4. Transverse section through a mesentery,

Edwardsia carnea, Gosse.

5. Transverse section through the parietal muscle of a mesentery, — .

C

6. Transverse section through a longitudinal retractor muscle, ^.

JTalcampa chrysanthellum (Peach).

2

7. Transverse section through a fertile (male) mesentery, — .

■A.

Halcampa arenarea, Haddon.

2

8. Transverse section through the oesophagus, -=r.

2

9. Transverse section through a fertile (female) mesenteiy, ^.

10. Section through an ovum, showing the formation of a polar-body while still

2

withm the mesentery, — .

Trans.R.Dub.S.,N.S.,Vol IV.

Plate XXXVI

EXPLANATION OF PLATE XXXVII.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART V.

PLATE XXXVII.

a., . .
ax. t., .
e. m., .
e. m. en.,

Ml., . .

a., . .

ec, . .

en., . .

g. >., .

I. ex., .

m., . .

Figure.
1.
2.
3.

4.
5.
7.

8.

9.
10.

11.
12.

13.

14.

15.
16.

17.
18.

LETTERING ADOPTED IN ALL THE FIGURES.

acontia.

m.f., .

. mesenterial filament.

s. d., .

. sulcar directive mesentery.

axial tentacle.

»., . .

. nucleus.

s. 1. en.,

Bulco-latcral endoccele.

circular muscle.

ces., .

. oesophagus.

si, . .

. sulculus.

circular muscles of endo-

ces. gr.,

. oesophageal groove.

si. (1., .

. sulcular directive mesen-

derm.

ov., . .

. ovum.

tery.

cuticle.

p. d., .

. pedal disk.

si. en., .

. sulcular endoccele.

directive mesenteries.

p.m., .

. parietal muscle.

si. ex., .

. sulcular exoccele.

ectoderm.

r. m., .

. retractor muscle.

si. 1. en.,

. sulculo-lateral endoccele.

endoderm.

sc., . .

. sucker.

s. 1. m.,

. sulco-lateral mesentery.

grains of sand.

s., . .

. sulcus.

si. 1. m.,

sulculo-lateral mesentery.

lateral exoccele.

s. en., .

. sulcar endoccele.

sp., . .

. sperm-cell.

mesoglcea.

s. ex., .

. sulcar exoccele.

z., . .

. zooxanthellse.

Diagrammatic section through the oesophageal region of Zoanthus.
Diagrammatic section through the oesophageal region of Epizoanthus.

Diagrammatic section through the oesophageal region of a young Zoanthus, slightly modified

from H. Hertwig (*. e. the retractor muscles of the mesenteries are added).
Diagram of a larval Zoanthus (" Microgrundform ").
Diagram of a larval Epizoanthus (" Macrogrundform ").

Larva of Halcampa chrysanthellum. A, diagrammatic transverse section through oesophageal
region ; B, similar section through digestive region.

Larva of Actinia equina (after Lacaze Duthiei's), first appearance of mesenteries, a, Smaller
chamber (sulcar endoccele) ; a', larger chamber (sulcular endoccele) ; 1, first pair of mesen-
teries.

Larva of Actinia equina (after Lacaze Duthiers). Stage of four mesenteries. (Lettering as

before) b, first lateral chamber (sulcular exoccele) ; 2, second pair of mesenteries.
Larva of Actinia equina (after Lacaze Duthiers). (Lettering as before) c, second lateral
chamber (sulcar exoccele) ; d, third lateral chamber (sulculo-lateral endoccele) ; 3 and 4,
third and fourth pairs of mesenteries.
Larva of Actinia equina (after Lacaze Duthiers). Octoradiate stage. (Lettering as before.)
Larva of Actinia equina (after Lacaze Duthiers). Later stage than fig. 11. (Lettering as

before) e, fourth lateral chamber (lateral exoccele) ; /, fifth lateral chamber sulco-lateral

endoccele) ; 5 and 6, fifth and sixth pairs of mesenteries.
Larva of Actinia equina (after Lacaze Duthiers). Optical section of same stage as last.

(Lettering as before.) The mesenterial filaments have a size proportional to the

order of their development.
Larva of Actinia equina (after Lacaze Duthiers). Three stages in the development of the

tentacles — A, stage with only one tentacle ; B, octoradiate stage ; C, stage with twelve

tentacles ; a, sulcar ; a', sulcular extremities of axial line.
Larva of Bunodes verrucosa (after Lacaze Duthiers). Oral end of octoradiate stage, a, sulcar

tentacle ; a', sulcular tentacle.
Larva of Bunodes verrucosa (after Lacaze Duthiers). Optical section of an early stage, with

twelve chambers — a, sulcar endoccele ; a', sulcular endoccele ; b, sulcular exoccele ; c, sulcar

exoccele; d, sulculo-lateral endoccele; e, lateral exoccele; /, sulco-lateral endoccele;

1, first pair of mesenteries developed with craspeda.
Adamsia diaphana (after 0. and E. Hertwig). A, diagrammatic transverse section through

the oesophageal region of a young form ; B, similar section, through an older individual.
Diagrammatic transverse section through the digestive region of a larval Cereus pedunculatus.

of the North Atlantic and North-Western Europe.

247

ADDENDA ET COKRIGEND A.

Cypria serena (Koch) (p. 70).

Fossil. — Tertiary : English Crag (Jones, as C. ovum).

Page 73, line 6, for " Cypris fuscata " read " Monoculus fuscatus."

Erpetocypris reptans (Baird) (p. 84).
Fossil. — Tertiary : English Crag.

Potamocxjpris fulva, Brady (p. 93).

Distribution. — Dr. Wilhelm Miiller has lately sent us this species from Greifswald, Germany. This
is the first time it had been found, we believe, on the Continent.
Fossil. — Post-tertiary : Scotland (Dalmuir).

Paracypris polita, G. 0. Sars (p. 95).
Fossil. — Tertiary : Antwerp Crag.

Candona Candida, Baird (p. 98).
Fossil. — Post-tertiary : England, Scotland. Tertiary : English Crag.

Candona hyalina, Brady and Bobertson (p. 104).

1870. Candona hyalina, Brady and Bobertson, Ann. and Mag. Nat. Hist., ser. iv., vol. vi., p. 18 ; pi. ix.,
figs. 5-8 ; and pi. v., figs. 4-11.

Shell of the male, seen from the side, elongate, flexuous, highest behind the middle, height equal
to half the length ; anterior extremity narrow, rounded, but somewhat flattened ; posterior broader and
well rounded ; dorsal margin forming a rounded gibbous prominence behind the middle, then sloping
with a long, gentle curve to the front — much more steeply, and with a hollow curve, backwards;
ventral margin deeply sinuated in the middle. Seen from above, the outline is much compressed,
ovate, widest in the middle ; extremities equal, and acutely pointed, width scarcely equal to one-third
of the length ; hinge margins flexuous, that of the left valve overlapping the right with a gentle curve
in front of the middle, and with a very abrupt and short but strongly-marked curve near the posterior
extremity. Shell very thin and translucent. Antennules slender, and very sparingly setiferous.
Caudal rami bearing two long and nearly equal terminal claws, and one minute seta, also a long and
slender lateral seta attached a little beyond the middle of the ramus. Verticillate sac destitute of
radiating filaments, except on the apical whorl. Copulative organs extremely complex. Apical joint
of the second foot bearing three very long and slender setae but no hook, penultimate joint with a single
seta of moderate length. Length of shell, 1-4 mm.

TBjLNS. EOT. DUB. SOC, N.S. VOL. IV., PART II. 2 K

248

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

The single specimen on which the foregoing description is founded having been mislaid, we were unable,
while engaged in the examination of the Candonce for the purposes of this Memoir, to verify the original
description,* and came to the conclusion that C, hyalina was probably only C. fabosformis, a species
which, when C. hyalina was described, was very imperfectly known to us. But the dissection of the
male type specimen of C. hyalina has since been found, and we have now no doubt whatever as to its
specific distinctness. As to the specimens ascribed by Messrs. Brady and Bobertson to the females of

this species, we are unable to express any decided opinion. The question needs to be considered afresh
with the help of a larger series of specimens. The specimen here figured, which is the only one upon
which we can pronounce certainly, was taken at Barton Broad, Norfolk. The other localities given
by Brady and Robertson are, Whittlesea, Wroxham, and Ormesby Broads.

The drawing here given of the verticillate sac is quite diagrammatic, the specimen having been too
much distorted in mounting to be represented, as it is now seen in the dissected mounting.

llyocypris yibba (Ramdohr) (p. 107).
Fossil. — Tertiary : English Crag.

Darwimda stevemoni, Brady and Bobertson (p. 122).
Fossil. — Post-tertiary : England (Whittlesea).

Cythere (?) semijninctata, Brady (p. 130).
Fossil. — Post-tertiary : Scotland (Oban).

Cythere semilunaris = Cythere amissa (p. 136).

"We find that Cythere amissa is a name already in use, having been employed by Prof. T. R. Jones
for an Eocene Fossil (Geological Magazine, 1870, vol. vii., p. 156) ; we therefore substitute C. semi-
lunaris as the name for the species which we have described.

Candona hyalina (male).

1 . Shell, seen from left side.
3. Extremity of second foot.

2. The same, seen from above.
4. Verticillate sac (diagrammatic).

5. Caudal ramus.

* See p. 104.

of the North Atlantic and North- Western Europe.

Cythere gibbosa, Brady and Robertson (p. 136).
Fossil. — Post-tertiary : Ireland (Portrush).

Cythere convexa, Baird (p. 140).
Fossil. — Tertiary : English Crag.

Cythere limicola (Norman) (p. 142).
Fossil. — Tertiary : Antwerp Crag.

Cythere hoptonensis, Brady, Crosskey, and Robertson (p. 158).
Fossil. — Post-tertiary : England (Hopton Cliff).

Cythere concinna (Jones) (p. 162).
Fossil. — Tertiary : English Crag.

Cythere daivsoni, Brady (p. 166).
Fossil. — Tertiary : (?) Antwerp Crag.

Krithe bartonensis (Jones) (p. 179).
Fossil. — Tertiary : English Crag.

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[257]

258 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

WORKS AND PAPERS CONSULTED IN THE PREPARATION
OF THIS MONOGRAPH.

Baird (W.) :

Natural History of the British Entomostraca (Mag. Zool. and Botany, vol. ii., 1838, p. 132).
Description of some new species and genera of British Entomostraca (Ann. and Mag. Nat. Hist.,

ser. i., vol. xvii., 1846, p. 410).
Note on the genus Cypridina, M. Edw., with description of two new species (Ann. and Mag. Nat.

Hist., ser. n., vol. i., 1848, p. 21).
Natural History of the British Entomostraca (Ray Society), 1850.

Description of several new species of Entomostraca (Proc. Zool. Soc, London, vol. xviii., 1850,
p. 254).

Monograph of the family Apodidm, and description of two new species of Cypris (Proc. Zool. Soc,

London, vol. xx., 1852. p. 1).
Some new species of Cypridina (Ann. and Mag. Nat. Hist., ser. ra., vol. vi., 1860, p. 139 ; and

Proc. Zool. Soc, London, vol. xxviii, 1860, p. 200).

Bosquet J.) :

Description des Entomostrac6s fossiles des terrains tertiaires de la France et de la Belgique,
Bruxelles, 1850.

Brady (G. S.)

Species of Ostracoda new to Britain (Ann. and Mag. Nat. Hist., ser. m., vol. xiii., 1864, p. 59).
Undescribed Fossil Entomostraca from the Brick-earth of the Nar (Ann. and Mag. Nat. Hist.,

ser. in., vol. xvi., 1865).
Report on Ostracoda dredged amongst the Hebrides (Brit. Assoc. Report, 1866, p. 208).
New and imperfectly-known species of Marine Ostracoda (Trans. Zool. Soc, vol. v., 1866, p. 359).
Entomostraca (Intellectual Observer, 1862, p. 446).

Synopsis of recent British Ostracoda (Intellectual Observer, 1867, p. 110).

Crustacean Fauna of the Salt Marshes of Northumberland and Durham (Nat. Hist. Trans.
Northumb. and Durham, vol. iii., 1868, p. 1).
/Monograph of recent British Ostracoda (Trans. Lin. Soc, vol. xxvi., 1868, p. 353).
^Contributions to the Study of the Entomostraca (Ann. and Mag. Nat. Hist., ser. iv., vol. ii., 1868,
pp. 30, 178, 220 ; vol. iii., 1869, p. 45 ; and vol. iv., 1870, p. 450).
Descriptions of Ostracoda (Berchon, De Folin, and Perier, Les Fonds de la Mer, vols, i., ii., and
iv., 1867-86).

Notes on the Ostracoda (Nares' Narrative of a Voyage to the Polar Sea, 1875-6, in H. M. S. S.

" Alert " and "Discovery," 1878, p. 253.)
Notes on Entomostraca taken chiefly in the Northumberland and Durham district (Nat. Hist.

Trans. Northumberland and Durham, vol. iii., 1870, p. 361).

of the North Atlantic and North -Western Europe.

259

Brady (G. S.) — continued :

Review of the Cypridinidae of the European Seas (Proc. Zool. Soc, 1871, p. 289).
Monograph of the Ostracoda of the Antwerp Crag (Trans. Zool. Soc, vol. x., 1878, p. 379).
Beport Voyage of H. M. S. " Challenger "—Ostracoda, 1880.

Notes on Entomostraca collected by Mr. A. Haly in Ceylon (Lin. Soc. Journal, vol. xix., 1885).
Notes on Freshwater Entomostraca from South Australia (Proc. Zool. Soc, 1886).
Notes on Entomostraca (Fifth Annual Report Fishery Board of Scotland, Appendix F, 1887,
p. 328).

Brady (G. S.) and Crosskey (W. H.) :

On Fossil Ostracoda from the Post-tertiary Deposits of Canada and New England (Geological
Magazine, vol. viii., 1871).

Brady, Crosskey, and Bobertson :

Monograph of the Post-tertiary Entomostraca of Scotland, and parts of England and Ireland
(Palseontographical Society, 1874).

Brady (G. S.) and Robertson (D.) :

Notes on a Week's Dredging in the West of Ireland (Ann. and Mag. Nat. Hist., ser. iv., vol. hi.,
1869, p. 353).

Ostracoda and Foraminifera of Tidal Rivers (Ann. and Mag. Nat. Hist., ser. iv., vol. vi., 1870, p. 1).
On the Distribution of British Ostracoda (Ann. and Mag. Nat. Hist., ser. iv., vol. ix., 1872,
p. 48).

Ostracoda taken among the Scilly Islands, and on the Anatomy of Danvinella stevensoni (Ann. and

Mag. Nat. Hist., ser. iv., vol. xiii., 1874, p. 114).
Report on Dredging off the Coasts of Durham and North Yorkshire (British Association Report,

1875, p. 185).

Carus (J. V.) :

Prodromus Faunas Mediterranean. Arthropoda, 1885.

Crosskey and Robertson :

Notes on the Post-tertiary Geology of Norway (Phil. Soc, Glasgow, 1868).

Claus C.) :

Ueber die Organisation der Cypridinen (Zeits. f. wiss. Zool., vol. xv., 1865, p. 143).

Zur naheren Kenntniss der Jugendformen von Cypris ovum (Zeits. f. wiss. Zool., xv., 1865, p. 391).

Ueber die Geschlechts differenzen von Halocypris (Zeits. f. wiss. Zool., xv., 1865).

Beitrage zur Kenntniss der Ostracoden (Schrift. der Gesells. z. Beford. d. gesam. Naturwis. zu

Marburg, Bd. ix., 1868, p. 151).
Neue Beobachtungen iiber Cypridinen (Zeits. f. wiss. Zool., xxni., 1873, p. 211).
Bemerkungen iiber marine Ostracoden aus den familien der Cypridinen und Halocypriden

(Arbeit. Zool. Inst. Wien und Zool. Stat. Trieste, t. vm., Heft 1, 1888, pp. 149-154, Wien).
Die Gattungen und Arten der Halocypriden, 1874.

Costa (0. G. and A.) :

Fauna del Regno di Napoli. Crostacei.

260 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Daday (E.) :

Catalogus Crustaceorum Faunae Transylvaniae, 1884.
Dahl (Feiederich) :

Die Cytlieriden der westlichen Ostsee (Zoologisch Jalirbuch, Bd. iii., Abtheilung fur Systematik,
1888).

Dana (J. D.) :

Crustacea of the United States Exploring Expedition, 1855.
De Saussure (H.) :

Memoire sur divers Crustaces nouveaux des Antilles et du Mexique (Mem. de Soc. de Physique et
d'Histoire Naturelle de Geneve, 1858).

Desmarest (A. G.) :

Considerations Generales sur la Classe des Crustaces (Paris, 1825).

Egger (J. G.) :

Die Ostrakoden der Mioean-Schichten bei Ortenburg (Stuttgart, 1858).
Fischer (S.):

Tiber die in der Umgegend von St. Petersburg vorkommenden Crustaceen aus den Ordnung der

Branchiopoden und Entomostraceen (Mem. des Sav. Etrangers., vii., 1847).
Abhandlung iiber das Genus Cypris (Mem. des Sav. Etrangers., vii., 1851).

Beitrag zur Kenntniss der Ostracoden (Abhandl. der mathemat.-physik. classe der Koniglich-
Bayerischen Akad. der Wissenschaft., vii., 1855, pt. 3).

Fischer (Dr. Paul) :

Crustaces Ostracodes Marins des Cotes du Sud-Ouest de la France, 1877.

Folin (Marquis De) :

Faune lacustre de l'ancien Lac d'Ossegor, 1879.

Fric, A.) :

Die Krustenthiere Bohmens, 1872.

Garbini :

Contrib. all 'Anatomia ed alia Istologia delle Cypridinae (Boll. Soc. Entom. Ital, xrx.).

Heller (C.) :

Untersuchungen iiber die Crustaceen Tirols, 1870.

Jones (T. B) :

Monograph of the Tertiary Entomostraca of England (Pakeont. Soc. 1856).

Notes on the Tertiary Entomostraca of England (Geological Magazine, vol. vii., 1870).

On some Fossil Ostracoda from Colorado (Geological Magazine, Decade n., vol. iii., 1886)

of the North Atlantic and North-Western Europe. 261

Jones (T. E.) and Sheeborn C. D.) :

Further Notes on the Tertiary Entomostraca of England, &c. (Geological Magazine, Decade ill.,
vol. iv., 1887).

Jurine (L.) :

Histoire des Monocles, qui se trouvent aux environs de Geneve, 1820.
King (E. L.) :

On Australian Entomostraca (Proc. Eoy. Soc. Van Diemen's Land, vol. hi., pt. 1, 1855).
Koch (C. L.) :

Deutschlands Crustaceen, Myriapoden und Arachniden, Heft. 10, 1837 ; H. 11, 1837 ; H. 12, 1837 ;
H. 21, 1838; H. 36, 1841.

Korschagin (A. N.) :

Fauna of the neighbourhood of Moscow, Entomostraca-Malacostraca, 1887, 4to (in Eussian).
Lilljeborg (W.) :

De Crustaceis ex ordinibus tribus Cladocera, Ostracoda et Copepoda in Scania occurrentibus, 1853.
Beskrifning ofver tva orter Crustaceen af ordningarna Ostracoda och Copepoda (Ofvers. af K. Vet.

Akad. Forhand, 1862, p. 391).
Collection of chiefly Freshwater Crustacea from Sweden (International Fisheries Exhibition,

London, 1883. Sweden Special Catalogue, p. 140).
De under Svenska vetenskapliga expeditionen till Spetsbergen, 1872-3, derstades samlade Hafs-

Entomostraceen (Kongl. Vetenskaps-Akad Forhand, xxxii., No. iv., p. 3, 1874).

Lubbock (J.) :

On the Freshwater Entomostraca of South America (Trans. Entom. Soc, vol. iii., N. S., pt. iv.,
1855).

On some Entomostraca collected by Dr. Sutherland in the Atlantic Ocean (Trans. Entom. Soc.

vol. iv., N. S., pt. ii., 1856).
On some Oceanic Entomostraca collected by Capt. Toynbee (Trans. Lin. Soc, vol. xxiii., p. 173,
1862).

Malcomson (S. M.) :

Eecent Ostracoda of Belfast Lough (Proc. Belfast Nat. Field Club, 1884-5, p. 259).
Moniez (E.) :

List des Copepodes, Ostracodes, Cladoceres, et quelques autres Crustaces recueilles a Lille en

1886 (Bull. Soc, Zool. de France, xii., 1887).
Note sur des Ostracodes, Cladoceres et Hydrachnides observes en Normandie (Bull. Soc. d'Etudes

Scient. de Paris, 1887).

Muller (Fritz) :

Bemerkungen iiber Cypridina (Jenaischen Zeitschrift, v., Heft. 2, 1870, p. 255).
Descripcao do Elpidium bromeliarum, crustaceo da familia dos Cytherideos (Archiv. d. Mus.
Nacional. Eio de Janeiro, iv., 1879, p. 27).

262 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Muller (0. F.) :

Zoologise Danicas Prodroruus, 1776.
Entomostraca, 1785.

Muller (Wilhelm) :

Zur naharen Kenntniss der Cytheriden (Archiv. fiir Naturgesch., 1884, p. 1).

Beitrag zur Kenntniss der Fortpflanzung und der Geschlechtsverhaltnisse der Ostracoden (Zeitsch,

f. d. gesarnm. Naturwiss., 1880, p. 21).
Uber die Function der Antennendriise der Cytheriden (Zeitsch. f. gesamm. Naturwiss., 1880.

p. 213).

Nordquist (Osc.) :

Beitrag zur Kenntniss der inneren mannlichen Geschlechtsorgane der Cypriden.
Norman (A. M.) :

Contributions to British Carcinology (Ann. and Mag. Nat. Hist., ser. in., vol. viii., 1861).

Species of Ostracoda new to Britain (Ann. and Mag. Nat. Hist., ser in., vol. ix., 1862).

Eeports Deep-sea Dredging, Coast of Northumberland and Durham — Crustacea (Nat. Hist. Trans.

Northumberland and Durham, vol. i., 1865).
Eeport of Committee for Exploring Coasts of the Hebrides (Brit. Assoc. Report, 1866, p. 198).
Last Eeport on Dredging among the Shetland Isles (Brit. Assoc. Report, 1868, p. 248).
Report " Valorous" Expedition (Proc. Roy. Soc, No. 173, 1876, p. 202).

Orley (S.) :

Uber die Entomostraken-Fauna von Budapest (Termeszetrajzi Fiizetek, x., 1886, pp. 7 and 98).
Pavesi (P.):

Altra serie di recheche e Studi sulla Fauna pelagica dei Laghi Italiani Padova, 1883.
Plateau (F.) :

Recherches sur les Crustaces d'eau douce de Belgique (Mem. Couronnes et Mem. des Savants
Etrangers, xxxiv., 1868).

Ramdohr (K. A.):

Beitrage zur Naturgeschichte einiger deutschen Monoculus-arten, Halle, 1805.
Reuss (A. E.) :

Die fossilen Entomostraceen des osterreichischen Tertiarbeckens (Naturwiss. Abhandlungen, iii.,
1847, p. 41).

Roohebrune (A. T.) :

Observations sur la Cypris fusca (Act. Soc. Lin. de Bordeaux, xxiv., 1861, p. 77).

Robertson (David) :

Notes on the Ostracoda and Foraminifera of the Firth of Clyde (Trans. Geol. Soc, Glasgow,

vol. v., pt. i., p. 112, 1874).
Notes on a Raised Beach at Cumbrae (Trans. Geol. Soc, Glasgow, 1875).

Notes on Cypris lasvis and its habit of perforating the leaves of Victoria regia (Proc. Nat. Soc,
Glasgow, vol. ii., 1875, p. 7).

of the North Atlantic and North -Western Europe.

263

Post-tertiary Deposit by Tunnel at Arkleston, near Paisley (Trans. Geol. Soc, Glasgow, 1876,
p. 292).

G arnoch Water Post-tertiary Deposit (Trans. Geol. Soc. Glasgow, 1876, p. 281).
Post-tertiary Deposit at Misk-Pit and Kilwinning (Trans. Geol. Soc, Glasgow, 1877, p. 297).
Notes on the Fauna and Flora of the west of Scotland, p. 38, 1876.
Post-tertiary Beds of Garvel Park, Greenock (Trans. Geol. Soc, Glasgow, 1883, p. 1).
E auna of Scotland, with special reference to Clydesdale and the western districts ; Fresh and
Brackish water Ostracoda. Glasgow, 1880.

SACCA'.iDO (PlETRO ANDREA) '.

Cenni Storico-naturali intorno agli animaletti Entomostracei, &c. Treviso, 1864.
Sars G. 0.) :

Qui en i Soinmeren 1862 fortagen Zoologisk Reise. Christiania, 1863.
Oversigt af Norges marine Ostracoder, 1865.

Nye Dybvandscrustaceer fra Lofoten (Vidensk.-Selsk. Forhand, 1869, p. 170).
Undersogelser over Christianiafjordens Dybvandsfauna, 1869.

Undersogelser over Hardangerfjordens Fauna, i., Crustacea (Vidensk.-Selks. Forhand, 1871, p 278).
Nye Bidrag til Kundskaben om Middelhavets Invertebratfauna. iv., Ostracoda Mediterranea (Archiv.
for Mathem. og Naturvidenskab, 1887).

Sars (Michael) :

Om de i Norge forekommende fossile dyrelivningen fra Quartferperioden . Christiana, 1865.
Schwarz (C. G.) :

Ueber die sogenannte " Schleimdriise " der mannlichen Cypriden (Berichten der Natur. f. Gesells.
zu Freiburg, Bd. m., 1888, p. 5).

Seguenza (G.) :

Le Formazioni Terziarie nella provincia di Reggio (Calabria), 1880.

II Quaternario di Rizzolo. ii., Gli Ostracodi (II. Naturalista Siciliano. Anno m., 1883).

Speyer (Oscar) :

Die Ostracoden der Casseler Tertiarbildungen. Cassel., 1863.

Stimpson (W.) :

Synopsis of the Marine Invertebrata of Grand Manan (Smithsonian Contributions, 1853).

Straus (H. E.) :

Me moire sur les Cypris (Mem. du Museum, vol. vii., 1821).
Stuhlman (F.) :

Beitrage zur Anatomie der inneren mannlichen Geschlechtsorgane und Spermatogenese der
Cypriden (Zeits. f. wissensch. Zoologie, xliv., 1887, p. 536; and, Zoologischen Institut. zu
Freiburg, i. B., 1886).

Terquem (M. 0.) :

Les Foraminiferes et les Entomostraces-Ostracodes du Pliocene sup^rieur de l'Ue de Rhodes (M6m
de la Soc. Geol. de France, ser. nt., vol. i., 1878).

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II. 2 M

264 Brady and Norman — Monograph of the Marine and Freshwater Ostracoda
Thomson (G. M.\:

New Zealand Entomostraca (Trans. New Zealand Institute, vol. xi., 1878).
Toth (Alex.) :

Die in neuester Zeit zu Pest-Ofen gefundenen Schalenkrebse und ihre anatomischen Vorhalt-
nisse (Verhdlgn. d. Zool.-bot. Ges. Wien., xiii., 1863, p. 47).

Vernet (H.) :

Acanthopus, un nouveau genre d'Ostracodes. (Forel, Materiaux pour servir a l'etude de la Faune
profonde du Lac Leman ive. Serie, 1879, p. 408.)

Weismann (A.) :

Parthenogenese, b. d. Ostracoden (Zool. Anzeig., vol. iii., 1880, p. 82).

Woodward (H.) :

A Catalogue of the British Fossil Crustacea. British Museum, 1887.

Zaddach (E. G.) :

Synopseos Crustaceorum Prussicorum Prodromus, 1844.

Zenker (W.) :

Anatomisch-systematische Studien iiberdie Krebsthiere. Berlin, 1854.

of the North Atlantic and North-Western Europe.

265

INDEX.

Note. — More Synonyms (in italics) are given in this Index than it was thought necessary to introduce
into the body of the work. The pages referred to under such a name contains the species of which such
additional name is the Synonym.

Acanthopus, 170.

elongatus, 170.
resistans, 176.

Aglaia, 94.

complanata, 94.
pulchella, 94.

Anchistrocheles, 110.

acerosa, 110.
fumata, 110.

Argillcecia, 111.

angusta, 111.
aurea, 122.
cylindrica, 111.

Bairdia, 112.

abyssicola, 241.
acanthigera, 113.
affinis, 242.
angulata, 114.
bosquetiana, 119, 120.
complanata, 116.
crosskeyana, 115.
dactylas, 107.
Mini, 242.
formosa, 113.
fulva, 93.

Bairdia.

hirsuta, 243.
inflata, 112.
minna, 117.
obliquata, 112.
obtusata, 116, 117.
punctata, 107.
simplex, 240.
subcircinata, 113, 240.
subdeltoidea (White), 112.
victrix, 115, 240.

Bairdiidse, 66, 112.

Bythocypris, 119.

bosquetiana, 119, 120, 243.
reniformis, 120.

Bythocythere, 220.

acuminata, 224.
bicristata, 222.
constricta, 220.
dromedaria, 223.
(?)flexuosa, 236.
insignis, 221.
pavo, 222.
recurva, 224.
recta, 222.
simplex, 224.
turgida, 221.

2 M 2

Candona, 98.

acuminata, 104.
albicans, 101.
Candida, 98, 247.
claviformis, 99.
compressa, 101.
detecta, 100, 102.
diaphana, 103.
elongata, 100.
euplectella, 105.
fabaeformis, 102, 103.
hispida, 73.
hyalina, 103, 247.
kingsleii, 102.
lactea, 100.
lucens, 98.
neglecta, 99.
parabolica, 106.
pubescens, 101.
reptans, 84.
rostrata, 101, 104.
serrata, 87.
similis, 84.
torosa, Jones, 175.
tumida, 98, 99.
virescens, 84.

Cyclocypris, 70.
globosa, 71.

Cypria, 68.

exsculpta, 68.

266

Brady and Norman — Monograph of the Marine and Freshwater Ostracoda

Cypria.

joanna, 70.
Icevis, 69.
ophthalmica, 69.
punctata, 68.
serena, 70, 247.
striata, 68

Cyprideis, 173.

lairdii, 173.
proxima, 173.
(?) pulchra, 173.
torosa, 175.

Cyprididse, 65, 68.

Cypridina, 212.
vespertilio, 212.

Cypridopsis, 89.

aculeata, 90.
newtoni, 90, 91.
olesa, 89.
picta, 92.
variegata, 91.
vidua, 89.
villosa, 90, 91.

Cypris, 73.

aculeata, 90.
adusta, 73.
affinis, 76.
angustata, 86.
aurantia, 73.
bicolor, 87.
liplicata, 107.
bimuricata, 96.
bispinosa, 82.
bistrigata, 107.
browniana, 72.
brunnea, 70.
(?) cambrica, 79.
Candida, 98.
cinerea, 71.

Cypris.

rmu'if q ftO

/mmj/m fiQ 70
ut'iv/fCy w, i \j.

ttjffljjf VOOlly

Ylfl.Ylf.llPYIMfl, fiM

JSli/fll/fVCf IfllVy \J C ■

Pflll Ptl ft PPff 7 Q
( V/lvflU/LLU>) i 17.

wfirfll)fil ton ftO

ffipllii Pi fl n 10.^

JJV'Vl tvl/ I fftfj J, uu,

PflW Pflffl 74

Yiip.tfi, Q9

/y fri/i/ifj • ' — •

n fin ) It Q — T\n tm 1 1 /icq 1 7^
U/vUlvlo — palJlllwoct, I/O.

qijlfiQft 74- 7.^

u pwi fit n WiA 'Y n i ti fi i ft Q7

ffWffff t/tf" llVWI U f/ftfflt , (/I i

r^vncirtn 7ft

flpfprfft 1 09

nnhpro 7.^ 74

dispctT) 97.

/V\ 1 1 1A f>T ft T ft |J O
P 11 fit I (ILlly Di7.

n/rnm pfl fiv )/i 1*1 ft 9

If/ V fit Vil li, 1 l It , i ( ■ 1 .

way) pfill fti n 74

f>] f>nrt^i i ill n fift AQ
C t c= y ill 1 1 11 Illy DOj Oj,

UUttLUllJal LI La, OO,

VPWt flY) <i ft 4

/ O fj t/lV ftO y O i .

clongtttd) 90.

Tcticulcitciy 76.

ephippidtdy 8 6 ;

W)l n i ft ft 70

/ llUt/VVlly i U.

t*t/Ot llOUVlly UO.

vn Vivn ft!?

fcicniofn ftl ftfi

RflltYlfi 7ft

OU/t/l ft/It/ y i O .

nCPrlPVi ftl
11 iM 1 1, O L*

flpvfl. 7 0

OV IVV ViJ Of liVy I \7 •

/7/7f;tf 97

It/lA/t/tt'y 1/ 1 t

Rpllii, 8 0

T'VP //"l J P ) O 7ft

Qpwpwft 70

»5t?/ V filly t \J •

RPTYfltfl, ft 7

fnc-nnfo 7Q

RPTTIll flf ft 1 07

Ot// / lAivliivtA, y i V 1 •

Tt/OfffTft I< <"\ fi rt W f\

J tCbCClod !, JVOCllj I u.

QPT^ftPV^ff 101
O&VlljKf Cly lull

ft ft If)) t) Pfl 7 3
ij Li/vU I fv Oil/ j t KJ*

aiiinatn, 107

aihhfi 1 07 94ft

UlUUlVy LV 1 y —TO.

vfi"} fiffi 74

Of/ tWftf , 1 TC .

// J n nPV")f 7/7 7 4
if ll/U £>f (A/t/Wiy t

stycmsi i y 83.

O'l nnncQ 7ft
j^lUUUoclj * O.

atvinflffi ft.^

O (// t U Llj 1/i.l y \J*J •

fjlobosdy 71.

Of/ lUlllilly DO.

nt' /i \i t/ 1 rtf ft A ft

y/ ciftuviiiu y do.

fpYiPYfl fiQ
VGfltsf tf,

mcczYKty 71.

4 GO Q oil SI i ft 1 C\

l&bb&l/Cilltl, I D,

lncougmens, 73.

fc/ ItJOflClllly OA.

iftstff/tiSy 76.

tristridtct, 74.

jocxHficiy 70.

T1IWl/)Tfff>Tft Q7
t ilftlVJ dtllly O / .

junnti, 85.

witfdscidtdj 75.

ICSllSy Out 1 U.

I'/tvo/t/ii/i P

(/«/ KlOlllOj ZfO.

Jpn)'f7i/7/7 &Q 70

I CJJ 111/14/1/11 y yJOy lu.

TPYitvi P(\^fl, 'I A

tstsfl/Uf lUUdtl'y $ I «

Icucowwld) 96.

1* 3 ft 1/ ft ft Q

lucidct) 85.

villosdy 90.

lllffiYi'fl ft£

rirpwR 74 70 ft'2

ffis I ft- li/lLVy \J ij ,

YiiLnflV) ft fiQ

i/iA/i/ifHf to, Ui/|

WlfWIflPnft Qfi
fills f (/lit filly isKJt

'Htpstif^nnn ) i QO
tvCof lAsUUlvt v y 3U.

IMfkllililPV'fl 7^
ffltsfllvlj V/Uj t O,

^Ptil'pyi ft7

XiVflfX/Vt l y Oil

monstrijica, 172.

nubilosa, 96.

obliqua, 77.

Cyprois, 96.

oblonga, 73.

ophthalmica, 73.

dentato-marginata

ornata, 77, 84, 85.

dispar, 97.

oyata, 82.

flava, 97.

Cypris.

of the Nor

•th Atlantic and North-Western Europe.

267

Cyprois.

Cythere.

Cytbere.

madaraszi, 97.

J "J ICO rt/i^

dictyon, 152, 244.

mytiloides, 107.

monacha, 96.

dorsoserrata, 135, 154.

navicula, 143.

drammensis, 137.

nigrescens, 200.

Cytbere, 125.

J.^T. * 1 fin

clubia, loz.

nitida, 188.

dunelmensis, 168.

nodosa, 142.

abyssicola, 156.

1 * i- -. 1 CA C% A A

ecnmata, 150, 244.

wm^«, 165.

acantboderma, 151,244.

emaciata, 159, 244.

oblonga, 138.

(?) acerosa, 110.

emargmata, 163.

pellucida, 126, 128.

alba, 138.

fidicula, 143.

pellucida, 127.

amissa, 136, 248.

finmarcbica, 163.

porcellanea, 127.

angulata, 165.

jlaviaa ^Zenker), loo.

prava, 160.

angustata, 172.

jlavida (±>aird), 226.

propinqua, 127.

antiquata, 168.

/T _ . • 7 _ /tit **n nun

jlaviaa (JVLuJier), 229.

pulcbella, 146.

arborescens, 140.

fuscata, 148.

punctata, 140.

areolata, 142.

gibba, 190.

quadridentata, 159.

audax, 167.

7 7. i r\A

giooera, 190.

relicta, 170.

aurantia, 188.

gibbosa, 136, 249.

reniformis, 125.

avena, 107.

globuliiera, 144.

rhomooidea, liscber, 185

badia, 130, 131.

guttata, 436.

rhomooidea, Brady, 216.

borealis, 147.

boptonensis, 158, 249.

robertsoni, 139.

bradii, 161.

impressa, 183.

rubida, 137.

brad it, 173.

,\ -t7 . f . 1 1 11

mjlata, 112.

runcinata, 160.

canadensis, 166.

inopinata, 170.

scaberrima, 245.

canaliculata, 132.

irpex, 150.

scabra, 151.

carinata = impressa, 183.

jenreysii, 142.

scabrocuneata, 154.

castanea, 126.

]onesn, 169.

semilunaris, 248.

catenata, 150.

lacustris, 176.

semipunctata, 130, 248.

-77 7 o r\

cellulosa, 206.

ICBVCltCty lot).

septentrionalis, 149.

ceratoptera, 169.

lameliiiera, 155.

setosa, 125.

cicatricosa, 140.

laticarina, 142.

simplex, 224.

cicatricosa, 131, 132.

latimargmata, 15 b, 161.

spectabilis, 169.

clathrata, 161, 165.

latissirna, 207.

speyeri, 141.

clavata, 162.

leioderma, 139.

stimpsoni, 160.

clutbae, 145.

iimicolaj 14^, i4o, z4y.

subcoronata, 169.

complexa, 145.

lepiaa, lot .

subdeltoidea, 112.

concinna, 162, 249.

1 «<J IOC

livtea, 125.

subflavescens, 176.

contorta, 325.

lyrata, 157.

sulcifera, 133, 243.

convexa, 132, 140, 141,249.

macallana, 128.

tenera, 129.

corpulenta, 134.

maccbesneyi, 149.

teres, 133.

costata, 164.

mamillata, 130.

trispicata, 155.

crenulata, 158.

marginata, 142.

tuberculata, 161.

cribrosa, 132.

milne-edwardsii, 244.

variabilis, 229.

crispata, 131.

mmna, 117.

ventrieosa, 143.

cuneiforniis, 143.

mirabilis, 168.

villosa, 146.

dasydernaa, 153.

monacantha, 150.

viridis, Brady, 125.

dawsoni, 166, 249.

mucronata, 165.

viridis, Miiller, &c, 185.

debilis, 173.

multifora, 185.

viridis, Zenker, 188.

declivis, 178.

mutabilis, 161.

wbitei, 169.

268 Brady and Norman — Monograph of the Marine and Freshwater Ostrocoda

Cythereis, 146.

angalata, 165.
antiquata, 168.
clavata, 162.
comuta, 169.
dunelmensis, 168.
emarginata, 146.
fimbriata, 169.
horrida, 168.
jonesii, 169.
limicola, 142.
mucronata, 165.
spectabilis, 169.
sj» inosissima, 165.
tuberculata, 161.
vittosa, 146.
ivhitei, 169.

Cytherida?, 69, 123.

Cytheridea, 172.

castanea, 175.
cornea, 172.
dentata, 178.
elongata, 172.
inaequalis, 178.
inermis, 178.
fascis, 179.
littoralis, 175.
lacustris, 176.
margaritea, 190.
miillcri, 172.
papillosa, 173.
punctillata, 173.
similis, 174.
sorbyana, 178.
stigmosa, 174.
(?) subflavescens, 176.
ta, 175.
torosa, 175.
tumida, 188.
zetlandica, 98.

Cytherideis, 226.

fasciata, 226.
flavida, 226.

Cytherideis.

foveolata, 227.
Mrfa, 226.
subulata, 226.

Cytherina, 188.
tumida, 188.

Cytherois, 227.

fischeri, 228.
virens, 228.

Cytheropsis, 178.

argus, 178.
tenuitesta, 178.

Cytheropteron, 207.

alatum, 214.
angulatum, 217.
arcuatum, 213.
convexum, 207.
crassipinnatum, 212.
depressum, 218.
hamatum, 212.
humile, 219.
inflatum, 209.
inornatum, 214.
intermedium, 211.
heve, 210.
latissimum, 207.
montrosiense, 216.
mucronalatuni, 215, 246.
multiforum, 185.
nodosum, 208.
pyramidale, 208.
rectum, 222.

subcireinatum, Brady, 218.
subcircinatum, Sars, 209.
testudo, 219.
tricorne, 211.
vespertilio, 212.

Cytherura, 190.

acuticostata, 195.
affinis Brady, 192.
affinis, Sars, 193, 200.
angulata, 197.
atra, 197.
cellulosa, 206.
clathrata, 206.
concentrica, 200, 201.
cornuta, 192.
cristata, 204.
cuneata, 194.
exserta, 204.
flavescens, 194.
fulva, 205.
gibba, Brady, 192.
gibba, Miiller, 190.
groenlandica, 204.
Jiumilis, 198.
insolita, 198.
lineata, 192.
nana, 206.

nigrescens, 200, 201, 202.
propinqua, 203.
producta, 199.
pumila, 198.
quadrata, 196.
robertsoni, 190.
rudis, 201, 204.
sarsii, 200, 203.
sella, 194, 200, 204.
similis, 200, 205.
simplex, 200.
striata, 196.
undata, 198.

Darwinulidse, 66, 121.

Barwinella, 121.
tstevensoni, 122.

Darwinula, 122.

stevensoni, 122, 248.

of the North Atlantic and North-Western Europe.

269

Erpetocypris, 84.

fasciata, 86.
olivacea, 88, 89.
reptans, 77, 80, 84, 247.
robertsoni, 88.
serrata, 87.
strigata, 80, 85, 88.
tumefacta, 87.

Eucy there, 178.

anglica, 178.
argns, 178.
declivis, 178.
prava, 178.

Ilyocypris, 106.

gibba, 107, 248.

Ilyobates, 179.

bartonensis, 179.
pratexta, 179.

Jonesia, 224.

simplex, 224.

Krithe, 179.

angusta, 181.
bartonensis, 179, 249.
glacialis, 180, 182.
producta, 180, 246.
reniformis, 182.

Limnicythere, 170.

compressa (var.), 170.
inopinata, 170.
moDstrifica, 172.
relicta, 170.
sancti-patricii, 171.

Loxoconcha, 183.

cuneiformis, 186.
elliptica, 185.
fragilis, 187.
granulata, 184.
guttata, 184.
impressa, 183.
longipes, 186.
multifora, 185.
pusilla, 186.
rhoniboidea, 183.
tamarindus, 186.
viridis, 185.

Machaerina, 237.

amygdaloides, 238.
tenuissima, 238.

Macrocypris, 117.

angusta, 117, 243.
minna, 117, 243.
siliquosa, 118, 243.

Metacypris, 123.
cordata, 123.

Monoculus, 69.

aurantius, 73.
bistrigatus, 107.
candidus, 98.
f meatus, 73.
monaclxus, 96.
ophthalmicus, 69.
ornatus, 79.
ovatus, 74.
ovum, 69.
puber, 107.
ruber, 73, 83.
unifasciatus, 75, 77.
viduus, 89.
villosus, 90.
virens, 74.

Normania, 183.
grisea, 185.

Notodromas, 95.

madaraszi, 97.
monacha, 96.

Paracypris, 95.

polita, 95, 247.

Paradoxostoma, 229.

abbreviatum, 230.
arcuatum, 234.
cuneatum, 234.
dispar, 229.
ensiforme, 229.
fasciatum, 233.
fiseheri, 228.
flexuosum, 233.
hibernicum, 232.
hodgii, 235.
normani, 230.
obliquum, 230.
orchadense, 234.
produetum, 236.
pulchellum, 231.
(?) reniforme, 182.
rostratum, 235.
sarniense, 232.
tenerum, 236.
truncatum, 231.
variabile, 229.
vitreum, 232.

Paradoxostomatidae, 69, 229.

Podocopa, 65.

Polycheles, 121.

stevensoni, 122.

270 Brady and Nokman-

Pontocypris, 107.

acupunctata, 109.
hispida, 108.
(?) angusta, 111.
mytiloides, 107.
serrulata, 107.
trigonella, 109.

Potamocypris, 92.

fulva, 91, 93, 247.

-Monograph of the Marine and Freshwater Ostracoda, Sfc.

Pseudocythere, 225.
caudata, 225.

Scottia, 72.

browniana, 72.

Sclerochilus, 225.

abbreviates, 231.
contortus, 225.
gracilis, 228.

Xestoloberis, 188.

aurantia, 188.
dcprossa, 188.
intermedia, 189, 246.
labiata, 189.
margaritea, 189, 246.
nitida, 188.

Xiphichilus, 237.

amggdaloides, 237.
tenuissima, 237.

EXPLANATION OF PLATE VIII.

TRANS ROY. DUB. SOC, N.S. VOL. IV., PART II.

PLATE VIII.

Figure.

1. Cypris affinis, female, seen from left side, . . . x 40

2. ,, ,, ,, ,, above,

3. ,, olivacea, ,, ,, left side,

4. ,, ,, ,, ,, above,

5. ,, tumefacta, female, seen from left side, . . . x 40

6. ,, ,, ,, ,, above,

7. ,, ,, ,, end view,

8. ,, ornata, female, seen from left side, . . . x 20

9. ,, ,, ,, ,, above,
9a, ,, ,, portion of shell-surface (reflected light), . x 50

10. ,, dromedaria, female, seen from right side, . . x 22

11. „ „ „ „ above, . . „

12. ,, cambrica, female, seen from left side, . . . x 60

13. „ „ „ „ below, . . . „

14. Erpetocypris strigata, female, seen from left side, . . x 16

15. ,, ,, ,, above, . . ,,

16. Cypridopsis newtoni, female, seen from left side, . . x 50

17. „ ,, „ „ below, . . „

18. Cyprois flava, female, seen from left side, . . . x 22

19. ,, „ „ above, ... „

20. Cypridopsis variegata, female, seen from left side, . . x 60

21. „ ,, ,, above, . . ,,
21a. ,, ,, shell structure (transmitted light), . x 200

[2]

EXPLANATION OF PLATE IX.

PLATE IX.

Figure.

1. Candona fabaeformis, male, seen from left side,

2. „ „ ,, ,, above,

3. ,, ,, female, seen from left side,

4. „ „ ,, „ above,

5. Cypris birsuta, female, seen from left side,

6. ,, „ above,

7. Candona euplectella, seen from left side,

8. ,, ,, ,, above,
8a. ,, ,, shell structure,

9. ,, acuminata, female, seen from left side,

10. ,, ,, ,, ,, above,

11. ,, rostrata, male, ,, left side,

12. ,, ,, ,, ,, above,
12a, b. ,, ,, junr., ....

13. Erpetocypris fasciata, female, ,, left side,

14. „ ,, „ ,, above,

15. Cypris clavata, seen from left side,

16. ,, ,, ,, above,

17. Macrocypris angusta, seen from left side,

18. ,, ,, ,, above,

19. Candona kingsleii, male, seen from left side,

20. ,, ,, ,, ,, above,

21. ,, ,, female, ,, left side,

22. „ ,, ,, ,, above,

23. Scottia browniana, female, seen from left side,

24. ,, ,, „ ,, above,

[4]

Trans.R.Dub. S.. N.S.,Vol.lV

Plate

Geo West 4 Sons li£h et imp

EXPLANATION OF PLATE X.

PLATE X.

Figure.

1. Gaudona Candida, var. claviformis, male, seen from left side, x 36

2. „ ,, ,, ,, ,, above, . „

3. Cypris fischeri, female, seen from left side, . . . x 28

4. „ „ „ „ above, ... „

5. Candona acuminata, seen from left side, . . . x 40

6. ,, ,, ,, above, ... „

7. Darwinula stevensoni, female, seen from left side, . . x 40

8. ,, ,, „ ,, above, . . „

9. „ ,, „ „ below,

10. ,, ,, ,, ,, front, . . ,,

11. ,, ,, male, ,, left side, . . ,,

12. ,, ,, ,, ,, above, . . „

13. ,, ,, lucid spots more highly magnified.

14. Candona Candida, var, tumida, male, seen from left side, . x 36

15. ,, ,, ,, ,, ,, above, . ,,

16. ,, ,, ,, female, ,, left side, . ,,

17. ,, ,, ,, ,, ,, above, . ,,

18. Candona Candida, var., female, seen from left side (Ackworth), x 36

19. ,, ,, ,, ,, above, . . ,,

20. ,, ,, male, ,, left side (Chester Ed.), ,,

21. „ „ ,, „ above, . . „

22. ,, ,, female, ,, leftside (Chester Ed.),

23. ,, ,, ,, ,, above, . . ,,

24. ,, elongata, ,, ,, left side,

25. ,, ,, „ ,, above, ... ,,

26. ,, ,, male, ,, left side, . .

27. ,, ,, ,, ,, above,

28. Argilloecia cylindrica, seen from left side, . . . x 80

29. ,, ,, ,, above ,,

30. Cypridopsis picta, female, seen from right side, . . x 210

31. ,, ,, ,, „ above, ...

Trans.R.Dub. S., N.S.,Vol.lV

Plate X.

OceoWeBti Sons Ji£h et imp

EXPLANATION OF PLATE

PLATE XL

Cypria exscalpta (female).

Figure.

1. Antennule.

2. Antenna.

3. Mandible and palp.

4. Caudal ramus.

4a. Portion of shell of young.

Cypria ophthalnvica (male).

5. Second pair of maxilla.

6. Caudal ramus.

7. Verticillate sac.

8. The same, viewed endwise.

9. Copulative organs.

Cyclocypris globosa (male).

10. Antennule.

11. Antenna.

12. Second maxilla, left side.

13. ,, „ right side.

14. Foot of first pair.

15. ,, second pair.

16. Caudal ramus.

17. Verticillate sac.

18. Copulative organs.

Scottia broivniana (male).

19. Antenna.

20. Mandible and palp.

21. Second maxilla.

22. Last joint of second foot.

23. Caudal ramus.

23a. Claw of the same, more highly magnified.

24. Verticillate sac.

25. Copulative organs.

[All the figures highly magnified.]

[8]

G.S.Brady, del.

Geo West & Sons btb et imp

EXPLANATION OF PLATE XII.

TRANS. ROY. DUB. SOC, N.S., VOL. IV., PART II.

PLATE XII.

Figure.

1 . Erpetocypris fasciata, end of caudal ramus.

2. Cypris fischeri, caudal ramus.

3. ,, fuscata, shell showing (a) outer, and (l>) inner, pigmented layer.

4. ,, ,, caudal ramus.

5. ,, affinis, portion of shell.

6. ,, „ „ ,, (young).

7. ,. ,, caudal ramus.

8. ,, incongruens, portion of shell.

9. ,, ,, caudal ramus.

10. ,, ohliqua, portion of shell.

11. Erpetocypris strigata, portion of shell (young).

12. Cypris hirsuta,

Cyprois flam.

13. Antenna.

14. Mandible and palp.

15. Second maxilla of female.

16. ,, ,, male (right side).

17. ,, ,, ,, (prehensile portion of left side).

18. Extremity of second foot.

19. Verticillate sac of male.

20. Copulative organs of male.

21. Portion of shell.

Condona rostrata.

22. Antennule.

23. Antenna.

24. Second maxilla of male.

25. Extremity of same seen obliquely (right side).
2G. „ „ „ (left side).

27. Extremity of second foot.

28. Caudal ramus.

29. Verticillate sac of male ; (a) vas deferens.

30. Copulative organs of male.

31. Portion of shell (young).

Candona pubescens.

32. Antenna.

33. Second maxilla of male (right side).

34. „ „ „ (left side).

35. Caudal ramus.

36. Portion of shell of adult.

37. Portion of shell of young.

38. Caudal ramus.

[The figures are all highly magnified, and those of shell structure are as viewed by transmitted light.]

[10]

S.S.Brady, del

Geo West 8. Sons l\th et lirtp

EXPLANATION OF PLATE XIII.

PLATE XIII.

Danrinula stevensoni.

1. Antennule.

2. Antenna.

3. Mandible and palp.

4. First maxilla.

5. Second maxilla and palp.

6. Foot of first pair.

7. ,, second pair.

8. Extremity of abdomen.

9. Copulative organ of male.

Metacypris cordata.

10. Antennule.

11. Antenna.

12. Mandible and palp.

13. Maxilla.

14. Foot of first pair.

15. ,, second pair.

16. ,, third ,,

17. Copulative organ of male.

Erpetoct/pris twin; facta .

18. Antenna.

Candona kinydeii.

19. Mandible of male.

Bairdia complanata.

20. Antennule.

21. Antenna.

22. Mandible.

23. Maxilla.

24. First foot.

25. Second foot.

26. Caudal ramus.

Erpetocypris reptans.

27. Antenna.

Candona parabolica.

28. Animal seen from left side, magnified.

29. ,, ,, above,

30. ,, ,, natural size (after Kocli).

[12]

G S.Brady, del.otUtk.

Geo West & Sons uric

EXPLANATION OF PLATE XIV.

PLATE XIV.

( 'yclocypris globosa .

Figure.

1. Shell of male, seen from left side, . x 50

2. ,, ,, ,, above, . ,,

Metacypris cordata.

3. Shell of female, seen from left side, . x 84

4. ,, ,, ,, below,

5. ,, ,, ,, front,

6. ,, male, ,, left side,

7. ,, ,, ,, above,

8. Eight valve of female, seen from inside, ,,

9. Left ,, ,, ,, ,, ,,

10. Hinge margins, seen from above, . ,,

11. Ventral margins, seen from below, . ,,

12. Posterior margins, seen from behind, . ,,

Oythere peV/ucida.

13. Shell of female, seen from left side, . x 40

14. ,, ,, ,, above, . ,,

15. ,, male, ,, left side, . ,,

Cythcre confusa.

16. Shell of female, seen from left side, . x 40

17. „ „ ,, above,

18. ,, male, ,, left side, . ,,

Oythere macallanu.

19. Shell of female, seen from left side, . x 60

20. ,, „ „ above, . ,,

21. ,, male, ,, left side, . ,,

Figure.
22.
23.
24.

25.
26.
27.

28.
29.

30.
31.

32.
33.

34.
35.

36.
37.

Cy there porcellanea .

Shell of female, seen from left side, . x 60

„ ,, ,, above, . ,, ■

,, male, ,, left side, . ,,

Cythcre clutlice.

Shell, seen from left side, . . . x 100
,, ,, above, „
,, below, „

Aglaia complanata.

Shell, seen from left side, . . . x 60

,, ,, above, . . . ,,

Cythere gibbosa.

Shell, seen from left side, . . . x 80

,. „ above

Cythere robertsoni.

Shell, seen from left side, . . . x 84

,, ,, above, . . . ,,

B yth ocypris bosq uetia mi.

Shell, seen from right side, . . . x 50
„ „ above, „

Cythere teres.

Shell, seen from left side, . . . x 80
,, ,, above, „

[14]

-ans.R.Dub. S.. N.S.,Vol.lV

S.Brady, del.

Geo West & Sons li£h.etimj>

EXPLANATION OF PLATE XV.

[15]

PLATE XV.

Figure.

1.

2.

3.

4.

5.

6.

7.

8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.

Cy there crispata, seen from left side,
,, ,, ,, above,

,, badia, ,, leftside,

,, ,, ,, above,

,, crenulata, seen from left side,
,, ,, ,, above,

,, pulchella, ,, left side,
,, ,, ,, above,

,, fuscata, male, seen from left side,
>> >> » „ above,

,, ,, female, ,,

,, leioderma, ,,

left side,
left side,
above,
left side,
above,
left side,
above,
left side,
above,
left side,
above,
left side,
above,
left side,
,, ,, seen from above,

boptonensis, seen from left side,

,, ,, above,

scabrocuneata, right valve, from outside,

,, above,

runcinata (male ?) seen from left side,
,, ,, ,, above,

canadensis, ,

latimarginata,

borealis, female,

lepida,

rubida,

runcinata (female ?

x 80
x 70
x 50

40

60

>i

50

II

40

1 9

50

l »

60

»»

40

n
50

)>

40

[16]

Trans.R.Dub. S, N.S.,Vol.lV Plate XV

1 2 3 4 5 6

G S.Brady, del

Geo West & Sons lvth el imp

EXPLANATION OF PLATE XVI.

TRANS. ROY. DUB. SOC, N.S., VOL. IV., PART II.

PLATE XVI.

Figure.

1.

2.

3.

4.

5.

6.

7.

8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.

trispicata, right valve,
costata, female,
echinata, ,,

Cytliere emarginata, female, seen from left side,

above,

bradii, ,, ,, left side,

above,
outside,
above,
left side,
above,
left side,
above,

,, corpulenta, female, seen from left side,

„ ii above,

,, septentrionalis, from left side,

,, below,
,, navicula, from left side,

,, below,
,, cribrosa, from left side,
,, ,, ,, above,

,, dawsoni, ,, left side,
,, i, above,

Cytheridea stigmosa, from left side,
,, ,, ,, above,

,, fascis, ,, left side,
„ above,
Xestoleberis margaritea, from left side,
,, ,, ,, above,

,, labiata, ,, left side,
,, ,, ,» above,

x 50
x 60

If

x 40

»>

> J
99

x 80
x 40

99

x 84
x 60

99
J J

x 100

II

x 60

99

x 50

[18]

Trans R. Dub. S, N S.,Vol.lV

Plate XVI.

12

18

22

28

S Brady, del

GeoWesti Bonn luh et imp

EXPLANATION OF PLATE XVII.

PLATE XVII.

Figure.

1. Liinnicythere sancti-patricii, male, seen from left side,

2. „ „ „ „ ,, above,

3. Bairdia crosskeiana, seen from left side, .

4. ,, ,, ,, above,

5. Krithe producta, female, seen from left side,

6. • ,, ,, ,, ,, above,

7. ,, ,, male, ,, left side,

8. Liinnicythere relicta, seen from left side,

9. ,, „ ,, above,

10. Krithe angusta, female, seen from left side,

11. ,, ,, ,, ,, above,

12. ,, ,, male, ,, left side,

13. ,, ,, ,, ,, above,

14. Cythere audax, right valve, seen from outside,

15. ,, ,, ,, ,, above,

16. ,, speyeri, seen from left side,

17. ,, ,, „ above,

18. Liinnicythere inopinata, var. compressa, seen from left side

19. ,, ,, „ ,, above,

20. Machaerina amygdaloides, seen frorn right side,

21. ,, ,, ,, below,

22. Cytherura atra,:;: seen from left side,

23. ,, ,, ,, above,

24. Loxoconcha pusilla, seen from left side, .

25. ,, ,, ,, above,

26. Cytheridea similis, left valve, seen from outside,

27. „ ,, ,, „ below,

28. Cytherura concentrica (?), young shell, seen from left side

29. ,, ,, „ „ above,

30. Cythere m'chesneyi, right valve, seen from outside,
81. „ „ „ „ above,

32. Loxoconcha fragilis, male, seen from left side,

33. ,, „ „ „ above, .

34. ,, „ female, ,, left side, .

35. Cythere cluthae, left valve, seen from outside, .

36. „ „ „ ,, above, .

x 60
x 40
x 40

» t
J J

x 60

x 80
> i
i >
» »

x 40

» »

x 50
x 60
x 40

M

x 84
i»

x 40
x 80
x 50

»»

x 70

1)

x 80

* The outlines are after G. 0. Sars, the sculpture from a fossil specimen.

[20]

EXPLANATION OF PLATE XVIII.

PLATE

XVIII.

Cytheritra simplex.

Figure.

1. Shell, seen from left side, x 100

2. ,, ,, above, ,,

Cytlierura sella.

3. Shell of male, seen from left side, x 100

4. ,, ,, ,, above,

5. ,, female, ,, left side ,,

6. ,, ,, ,, above, „

Cytherura similis

7. Shell of female, seen from left side, x 80

8. „ male, „ ,,

9- ,, ,, above,

Cytlierura rudis.

10. Shell of male, seen from left side, ..... x 80

11. ,, ,, ,, above,

12. ,, female, ,, left side, ,,

Cytlierura yibba.

13. Shell of female, seen from left side, . . . . x 80

14. ,, above, ..... „

15. ,, male, ,, left side, ,,

16. ,, ,, ,, above, .....

Cytlierura striata.

17. Shell of female, seen from left side, x 100

18. „ „ „ above „

Cytlierura a finis.

19. Shell, seen from left side, x 80

20. ,, above, „

Cytlierura cornuia.

21. Shell of male, seen from left side, x 80

22. „ „ „ above „

Cytherura yroenlandica.

23. Shell, seen from left side, —

24. ,, ,, above, —

[22]

xans.R.Dub. S, N.S., Vol.1V

G.S Brady, del.

Geo "West 1 Sons btii et incLp

EXPLANATION OF PLATE XIX.

PLATE XIX.

Figure.

1.

2.

3.

4.

5.

6.

7.

8.

9.
10.
10a.
11.
12.
13.
14.
15.
1G.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.

Cytherura nigrescens, female, seen from left side,
>> " „ „ above,

,, concentrica, ,, left side,

,, ,, ,, above,

,, producta, ,, left side,

,, ,, above,

,, angulata, ,, left side,

,, ,, ,, above,

,, fulva, female, ,, left side,

,, ,, ,, ,, above,

,, ,, end view, ....

,, ,, male, seen from above,

,, undata, ,, right side (junior

Bythocythere recta, seen from left side, .
,, ,, ,, above,

,, bicristata, seen from left side,

,, ,, ,, above,

Cytheropteron angulation, seen from left side, .

,, ,, ,, above,

Cytherideis foveolata, ,, left side, .

„ ,, ,, above,

Cytherura rudis, rar., from left side,
Cythere sulcifera, left valve, from outside,
,, ,, ,, ,, above,

Bythocythere recurva, right valve, from outside,

>> „ >, above,

Cytheropteron montrosiense, left valve, from outside,
„ ,, ,, ,, above,

,, arcuatum, seen from left side,

,i „ above,

,, ,, ,, behind,

Cythere complexa, seen from left side,
ii ,, above,

100
80

x 40
x 80

x 66

x 80

x 50

x 80
x 40

9 >

x 80

>)
x 80

[24]

S.Brady, del

Geo West &, Sons lith et imp

EXPLANATION OF PLATE XX.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART II.

PLATE XX.

Figure.

1. Cytheropteron pyraniidale, male, seen from left side, . x 50

2. ,, ,, ,, „ above, . ,,
8. ,, ,, ,, ,, behind, . ,,

4. ,, humile, seen from left side, . . . x 80

5. ,, ,, „ above, ... „

6. ,, ,, below, ... ,,

7. ,, ,, ,, behind, ... „

8. ,, alatum, ,, left side, . . . x 50

9. ,, ,, above, ...

10. ,, ,, ,, behind, ... ,,

11. By thocy there dromedaria, seen from left side, . . . x 50

12. ,, ,, „ above, ... „

13. Cytheropteron hamatum, seen from left side, . . . x 60

14. ,, ,, „ above, ... „

15. ,, ,, ,, behind, . . . . ,,

16. .. crassipinnatum, seen from left side, . . x 80

17. ,,' ,, ,, above, . . ,,

18. ,, ,, ,, behind, . . ,,

19. ,, inflatum,* ,, left side, . . x 50

20. ,, ,, ,, above, . ,,

21. ,, ,, ,, behind, . . ,,

22. ,, depressum, ,, left side, . . x 80

23. ,, ,, ,, below, . . ,,
23«. ,, i, ,, end view, . . x 50

24. Cytherura exserta, seen from left side, x 100

25. ,, ,, above, .... „

26. Cytheropteron subcircinatum, seen from left side, . . x 80

27. „ above, . . ,,

28. ,, ,, ,, behind, . . ,,

29. ,, heve, right valve from outside, . . . x 50

30. „ „ left „ „ ...

31. ,, ,, ,, ,, from above, ... ,,

32. Cythere mamillata, left valve from outside, . . . y 80

33. ,, ,, ,, from above, ... ,,

* The figures of this species are drawn from a fossil specimen.

[26]

Trans.R.Dub. S., N.S.,Vol.lV

Plate XX

Q S.Brady, del.

Geo West t Sons iith et imp

EXPLANATION OF PLATE XXL

PLATE XXI.

Cytheropteron test/ado

Figure.

1. Shell, seen from left side, . , x 80

2. ,, ,, above, . ,,

Cytheridea castanca.

3. Shell, seen from left side, ...... x 40

4. ,, above,

Paradoxostoma arcuatum.

5. Shell, seen from left side, x 80

6. ,, ,, above, ,,

Paradoxostoma hodgU.

7. Shell, seen from left side, .... x 80

8. ,, ,, above, ,,

Paradoxostoma productum .

9. Shell, seen from left side, x 80

10. ,, ,, above, ,,

Para doxostom a flexuosum .

11. Shell, seen from left side, x 80

12. ,, ,, above, ,,

Machairina tenuissima .

13. Shell, seen from left side, ...... « 40

14. ,, „ above, „

Paradoxostoma hibernicnm .

15. Shell of female, seen from left side, .... x 60

16. „ ,, ,, above, ... „

17. ,, male, ,, left side, .... ,,

Paradoxostoma orchadense.

18. Shell, seen from left side, x 80

19. ,, ,, above

Cytherois fischeri.

20. Shell of female, seen from left side, .... x 80

21. ,, ;, ,, above,

22. ,, male, ,, left side ,,

Krithe reni/ormis.

23. Shell, seen from left side, x 80

24. ,, „ above, . ' „

Paradoxostoma fasciatum.

25. Shell, seen from left side, x 50

26. ,, ,, above, „

Para doxostoma vitreum.

27. Shell, seen from left side, x 80

28. „ ,, above, ,,

Paradoxostoma pidchellum.

29. Shell, seen from left side, x 80

80. ,, ,, above, ,,

Trans.R.Dub. S, N.S.,Vol.lV

Plate XXI.

S.Brady, del.

Geo "West & Scms liLhetirap.

EXPLANATION OF PLATE XXII.

PLATE XXII.

Ilyocypris gibba ( female).

Figure.

1. Antenna.

2. Mandible.

3. First maxilla.

4. Second maxilla.

5. Distal half of second foot.

Cytherura gibba.

6. Antennule.

7. Antenna.

8. Mandible.

9. First maxilla.

10. Copulative organs of male.

11. Terminal portion of same more highly magnified.

12. Portion of shell.

Potamocypris fulva.

13. Antennule.

14. Antenna.

15. Mandible.

16. Second foot.

17. Copulative organ of male, with coil of spermatic filaments.

Pontocypris trigonella.

18. Antennule.

19. Antenna.

20. Mandible.

21. Second maxilla of female.

22. Second maxilla of male.

23. Foot of first pair.

24. Foot of second pair.

25. Caudal ramus.

S.S.Brady, del.etUth.

Geo West, & 6on.s , ltoj).

EXPLANATION OF PLATE XXIII.

PLATE

XXIII.

Figure.

1. Bythocy there insignia,* shell, seen from right side, .

2. „ ,, „ above, . . —

3. Paradoxostoma rostratum,* shell, seen from right side,

4. ,, ,, ,, ,, left side, . —

5. Darwinula stevensoni, female, valve removed so as to show animal.
G. Pontocypris trigonella, female, .. ,,

7. Loxoconcha impressa, female, ,, ,,

8. Cytherura gibba,t male, ,, ,,

9. Bythocythere simplex, female, ,, ,,
10. Paradoxostoma variabile, male, ,, ,,

(«) antennule.
(6) antenna.

(c) poison-gland.

(d) flagellum.

(e) mandible.

(/) mandible-palp.
(</) labrum.

(h) labium.

(i) first maxilla.
(k) second maxilla.
( I) first foot.

(m) second foot.
(n) third foot.

(o) appendages at base of first pair of feet.

(p) abdomen.

(q) caudal rami.

(r) copulative organ of male.

(s) convoluted process of same.

(t ) ova.

* After drawings by Prof. G. 0. Sara.

t The mandible in fig. 8 is drawn out of position, and too near the front of the animal.

132]

[ 271 ]

III.

OBSERVATIONS OF THE PLANET JUPITER, MADE WITH THE REFLECTOR
OF THREE FEET APERTURE, AT BIRR CASTLE OBSERVATORY,
PARSONSTOWN. By OTTO BOEDDICKER, Ph. D. Plates XXIV. to XXX.

[Communicated by The Earl of Rosse, LL.D., F.R.S., President, November, 1888.]

The Drawings of the Planet Jupiter published herewith were made during the
years 1881 to 1886, at Birr Castle Observatory. During this time eighty com-
plete drawings and four sketches of single belts only were made, which are
distributed in the following way over the different oppositions : —

1881- 1882, twenty-two.

1882- 1883, thirty-one.

1883- 1884, twenty-one.

1884- 1885, eight.

1885- 1886, two.

The falling of! in numbers during the two last oppositions finds its explanation
in the fact, that my time was then thoroughly occupied by a large detailed
drawing of the Milky Way, which is now completed, and likely to be ready for
publication early next year.

The Jupiter drawings were all made with the reflector of three feet aperture ;
but as during the period of drawing the speculum had to be repolished repeatedly —
once a-year at least — it cannot exactly be said that they were all made under the
same instrumental conditions, the speculum being practically a new one after each
process of repolishing. The sketches were all executed with pencil and stump, not
more than ten minutes being on the average devoted to each of them. They are
reproduced by a photo-mechanical process by Wilhelm Hoffmann, Marschallstrasse,
Dresden, directly from the originals, in order to avoid the inaccuracies frequently
caused by the transferring lithographer. Besides this, the originals have not been
touched in any way whatever, as I consider the value of a reproduction like the

TRANS. BOY. DUB. SOC, N.S. VOL. IV., PABT III. 2 E

272 Boeddicker — Observations of the Planet Jupiter,

present one so much the greater, the more accurately it represents the drawings just
as they were obtained at the telescope. This accounts for some obvious errors, e. g.
the want of parallelism between the belts and the equator (very conspicuous in
Nos. 10 and 13). This is owing to an oversight in sketching; belts and equator
should, generally speaking, be parallel throughout. As the drawings had to be
executed by rather feeble lamplight, they will naturally most nearly represent what
was really seen by the observer if looked at in a similar light. This point seems
to deserve more attention than it usually receives. Many of the published drawings
show detail of a considerable and somewhat unnatural sharpness and boldness, a
feature which, to a considerable extent, disappears if those drawings are looked
at in the same subdued light in which they had to be done.

In the following I copy from my note-book the remarks made during each obser-
vation. All the explanation they require is this, that the Jovian belts are referred to
as a, b, c, &c, beginning with the most southern one as a. Thus the two most constant
and most conspicuous belts occur throughout as b and c. The intervals between
the belts are denoted by the names of these two belts in brackets [b c], meaning,
for instance, the interval between b and c. The " red spot" is referred to as s.

Without entering into a discussion of the drawings, I may, perhaps, direct
attention to the sketches Nos. 48, 49, and 50, which represent the same belt b at
short intervals of time. I have reproduced them because they illustrate a fact
often experienced by me ; viz. how what at first is only perceived as unmeaning
separate patches seems, in the course of prolonged examination, to combine with
fainter surrounding detail into an object of definite character. In our case, the
separate dark patches in No. 48, combined with fainter markings, become in Nos.
49 and 50 the shadows of large cumulus-like clouds, lying across the Jovian
surface in surprisingly strong relief. How far this process of combination is only
subjective it would be difficult to decide : if it is, it shows to how considerable an
extent the individuality or a preconceived idea of the observer may unintention-
ally affect the final appearance of an astronomical drawing. It remains to be
added, that the powers used were generally 144 and 216.

Notes to accompany the eighty-four drawings of the Planet Jupiter, as repre-
sented in Plates XXIV. to XXX :—

PLATE XXIV., FIGUEES 1 to 12.

September, 2, 1881.

1. 13h 12m. M. T. Grw. L = 58;-8. Very clear.

a greyish, southern edge very bright ; b and c reddish 3Tellow, equally dark;
d fainter, same colour ; bright line on b and d, in traces oik; e very faint,

made at Birr Castle Observatory, Parsonstown.

273

hardly perceptible ; no distinct clouds between the belts; the "red spot"
exceedingly red ; its following end seemed sometimes to be darker.

September 22, 1881.

2. No. 1. 12h 20m. L = 157°-l.

a faint, greyish ; b greyish red ; c decidedly red ; d same tint, but brighter ;
the whole disc pale; limb boiling. Some clearer moments at first, when
bright lines were perceptible on c and d; then e was more visible also.

3. No. 2. 13h 27m. L=197°-2. Exceedingly clear.

a faint, greyish, its southern edge very bright ; b and c almost equally dark,
hardly any colour perceptible ; d fainter, bright line on it ; e very faint. The
central cloud in \b c] very bright.

October 1, 1881.

4. No. 1. 12h 29m. L=77°-9.

a bluish grey, its south edge very bright, in south of it whitish patches ;
s brick red, a very white patch following it ; b reddish grey, interrupted ; c
brown red, darker than b; in [b c~\ cloud-like patches, near the following limb
of the disc two very bright ones ; d reddish grey, as dark as a ; e greyish
traces. Enormous quantity of detail.

5. No. 2. 13h 53m. L=128°-4. Definition considerably worse.

Colours not altered, but less distinct ; limb sometimes trembling ; d darker
than a. Central cloud very bright.

October 14, 1881.

6. 12h 17m. L=2270,2. Definition changeable, at times very good. Moonshine.

bed reddish yellow ; c d equally dark ; b darker ; a very faint, south-
edge of a rather bright ; bright line on d. In [b c] whitish clouds, not very
bright. I thought sometimes I saw bright parallel stripes on the northern
hemisphere.

October 15, 1881.

7. 12h 53m. L = 390,5. Very clear. Definition excellent. Enormous quantity

of detail. Colours very decided.

s bright brick red, blunt-pointed on both ends ; a bluish grey ; b same
colour, but darker ; c reddish yellow ; d same colour, but fainter. Clouds in

2 E 2

274

Boeddicker — Observations of the Planet Jupiter,

[b c] in very strong relief. In a near s white cloudish interruptions (small
spots). The faint features towards the poles bluish grey, with very bright
lines between.

October 30, 1881.

8. No. 1. 9h50m. L=27°"4. Definition and clearness moderate; sky slightly hazy.

Moonlight. Markings not very distinct. Sketch not very satisfactory.

s very red ; its following end a blunt point ; this at the preceding one not
so (if at all) conspicuous ; a greyish ; b c d reddish grey ; b darkest ; e sus-
pected. Hardly any markings in \b c]. Satellite shadow very dark.

9. No. 2. 12h 48m. L = 135°-3. Definition excellent.

a greyish with white patches ; b reddish grey ; the darkest part immediately
following the central meridian decidedly blue ; c and d brick red ; c some-
what darker than d ; e consists of bluish-grey spots. Very white clouds in
[be].

November 17, 1881.

10. 13h 8m. L = 336°-7. Very clear.

a bluish, patchy, one very bright stripe in it ; near s, especially near its
following end, rather dark ; s exceedingly red, flame-like brick red, slanting
towards south at its preceding end, not parallel with b ; its preceding end a
blunt point. In [a b~\ extremely faint bluish traces ; b bluish grey ; c and d
yellowish grey ; c darker than d ; on d light cloud-like patches ; e bluish, con-
sisting of two darker stripes (the northern of which repeatedly interrupted)
enclosing one very bright one.

November 19, 1881.

11. 10h 58m. L = 1990,4. Interrupted by clouds ; definition, however, pretty good.

Not much difference of colour ; the belts yellowish grey.

a considerably fainter than the other belts ; very bright white patches in it.
The northern shadows of the clouds in [b c] are bluish, especially that of the
cloud nearest to preceding limb. The division between the clouds just fol-
lowing the central meridian very blue, which becomes more conspicuous the
more the spot advances on the disc. Very bright lines in e. Delicate (greyish)
shading on the northern part of the disc.

made at Birr Castle Observatory ', Parsonstown,

275

November 24, 1881.

12. llh20m. L=245°-2.

a grey, the dark part just on central meridian bluish ; b e d yellowish
(orange); [a b~] very bright, the clouds in [b c] rather so ; the two small round
ones nearest to following limb very distinct. I thought I saw white traces in
\_c d~\ and on d. Very bright patches (lines) in e. Greyish shading on the
northern part of the disc (north of e).

PLATE XXV., FIGrUEES 13 to 24.

November 25, 1881.

13. IP 6m. L = 27°-9. Striking difference of colours.

a bluish ; b more grey ; c d yellowish grey ; cloud-shadows in [b c] blue ;
e bluish grey Bright lines in south of a and in e ; clouds in [b c] bright.
Satellite on the disc very bright, at llh 14m the Satellite just emerging from,
and its shadow just entering on, the disc ; s exceedingly bright brick red,
flame-like, with blunt points ; these latter, however, not very distinct ; b c d
almost equal in darkness ; a somewhat fainter.

November 30, 1881.

14. 10h 44m. L = 46°5. Fairly clear. Moonshine.

a bluish, its southern limb very bright ; nothing with certainty seen in south
of it ; s very red, bright brick red, blunt points suspected, not very distinct;
b yellowish grey, cloud-shadows in [b c] blue ; c d more reddish yellow ; c in
north of central cloud darkest ; e bluish ; north of e delicate bluish-grey
shading. Difference of colour not very decided.

December 7, 1881.

15. 9h 2m. L = 3180,6. Definition pretty good. Bright moonshine.

Colours not very decided ; s brick red ; a (near s) and the cloud shadows in
[b c] bluish ; the central clouds [b c] very bright ; b c d yellowish, consider-
ably less distinct near the following limb than near the preceding one ; e con-
sists of a very bright line with a dark one in south and two bluish patches in
north.

276 Boeddickek — Observations of the Planet Jupiter,

December 9, 1881.

16. 10h 26m. L = 310°-l. Very clear. Definition very good.

a bluish, its following- part darkest ; s just with difficulty perceptible ; b c d
reddish yellow ; b darkest ; c perhaps equally dark. Cloud-divisions in [b c]
decidedly blue ; c bluish grey with bright lines. All the markings become
sooner indistinct towards the following limb than towards the preceding one.

December 14, 1881.

17. 9h 53m. L = 322°*4. Image very steady. Definition very good.

a yellowish, near s bluish ; s brick red, blunt point ; b c d reddish yellow,
cloud- divisions in [b c~\ bluish grey ; e grey with a very bright line. There is
a small white spot in b near the central meridian, and a darker one just over
the following cloud-division. Traces of white clouds in [c d~\.

December 21, 1881.

18. 8h 34m. L = 2470,7. Definition at times very good. Fog. Jupiter pale.

a rather faint, of a yellowish tinge ; bed reddish yellow ; the cloud-divisions
in [b c] decidedly blue ; e grey, as bright as a. The central cloud in [b c~\
very bright.

Jupiter was again examined about llh 30m by Lord Rosse. The
red spot looks mottled, at the ends considerably darker, especially at the pre-
ceding one. Between the two ends its appearance is streaky, with darker and
brighter patches.

December 22, 1881.

19. Time (?) Fog. Definition excellent. Image perfectly steady.

s very brick red, its following end darker ; just preceding this end a whitish
spot on s ; the whole of s streaky. In the drawing these markings perhaps a
little too dark and too distinct. The colours of the belts not very decided ;
a bluish grey ; b c d yellowish ; e consists of grey and silvery lines ; d of a
mottled appearance ; the divisions in [b c] not distinct, but certainly seen as
in drawing.

December 27, 1881.

20. No. 1. 8h Om. L = 50°-l. Definition good. Moonshine.

a bluish grey, patchy ; s brick red, with indistinct dark spots, as in sketch ;

made at Birr Castle Observatory, Parsonstown.

277

b bluish grey, mottled, interrupted by lighter and darker spots. The shade
in south of it, beginning just following s, decidedly yellowish red ; c of the
same colour ; divisions in [b c~] indistinct, grey ; (/yellowish red, very mottled,
with minute brighter and darker spots ; e consists of bluish grey irregular
patches ; [« b~] just following s, rather bright.

21. No. 2. 10h 2m. L = 1230,7. Definition good, yet the disc trembling at times.

Rather pale.

Colours as before, though not so decided ; a rather complicated, patchy,
difficult to draw ; b grey ; c d yellowish ; the cloud-division in [b c] just
following central meridian decidedly blue ; e faint, consists of bluish grey
patches and rather bright lines, difficult to draw.

Januaey 17, 1882.

22. 9h 49m. L = 33°-4. Clear. Definition pretty good.

s very red (brick red with orange tinge) ; its following end appeared at times
darker (as in sketch) ; a grey, not very distinct ; b yellowish grey, rather dark ;
c d yelle wish red, equally dark ; e bluish grey, patchy. The cloud-divisions
in [b e~\ bluish. South pole reddish ; north pole more bluish-grey shading.
The markings sooner indistinct towards the following than towards the pre-
ceding limb.

December 7, 1882.

23. No. I. 10h 50m. L= 167°-3. All details difficult and rather faint.

b reddish brown, darkest ; c (consisting of two stripes) much fainter. These
two stripes equally dark, or perhaps the northern one a little darker. In [b c]
white clouds, especially one on the central meridian, and a small round one
preceding it. The dark spot underneath the central cloud decidedly blue.

24. No. 2. 12h lm. L=210°-l. Definition better than before.

b reddish brown, equally shaded all over ; all other spots yellowish, except
the belt north of the equator, which is bluish, as also the central dark spot
in c. This spot slightly darker than the rest of c. Southern markings very
indistinct.

278

Boeddicker — Observations of the Planet Jupiter,

PLATE XXVI., FIGUEES 25 to 36.

December 8, 1882.

26. llh29m. L = 341°4. Definition rather good.

a and d bluish grey ; b reddish brown, interrupted as in sketch ; c pale
yellowish. In [b c] white clouds with bluish intervals, especially the two dark
spots in the following half quite blue. Detail between b and c, especially the
northern spots, not easy. Between the dark northern belts e very bright
intervals. The belts should be parallel to the equator.

December 22, 1882.

26. No. 1. 10h 44m. L=262°'2. Clear. Squally. Tube trembling. Disc pale.

b reddish yellow, its following part darkest ; interrupted by two small
white spots. The equatorial spots (in c) pale bluish grey.

27. No. 2. IP 54m (?). L = 304°-3 (?). Not quite so clear as before. Very bright

moonshine. Strong gusts; telescope continually trembling, drawing,
therefore, very difficult. Sketch not equally reliable in all parts.
Northern spots uncertain, also the preceding ones in [b c] immediately
near the preceding limb. Disc very pale.

b reddish brown; spots north of it (in c) bluish.

January 15, 1883.

28. No. 1. 10h 57m. L = 282o,0. Very clear and distinct. Moonshine. Disc

rather pale.

a and e very faint ; b reddish grey ; c consists of grey spots, with one very
conspicuous white one ; d yellowish grey.

29. No. 2. 12h 9m. L=3250,8. Very clear. Interrupted by passing cirri.

a and e faint ; e consists of different stripes. The dark parts in b reddish
brown, in c decidedly bluish grey, and darker than d.

January 18, 1883.

30. No. 1. 9h 53m. L=334°-6. Exceedingly clear ; very difficult.

a c d e /pale yellowish ; b reddish brown.

made at Birr Castle Observatory, Parsonstown. 279

31. No. 2. 10h 25m. L = 354o,0. Hazy, but definition very good. Air very steady.

s very pale pink, at first not recognized at all. Other colours as before.
In [c d ] faint patches, hardly to be made out.

32. No. 3. llh 26m. L=310,4. Definition worse, yet air steady. Rather thick

haze.

s pink, very faint ; b reddish brown. All the other spots indistinct and
difficult ; no special colour in them perceptible.

January 19, 1883.

33. No. 1. 9h 58m. L=128°-l. Very steady and well defined. Frequently

interrupted by clouds.

b reddish brown, ends abruptly at the preceding limb ; c consists of very
blue streaks. In [b c], just following the satellite-shadow, a rather white
spot ; [c d ] mottled ; e and / not with certainty seen divided ; in its following
half a bluish patch. Both poles shaded ; the northern one more so than the
southern one.

34. No. 2. 10h 35m. L=150o,5. Very clear. Interrupted by clouds. Clock

ran down. Satellite and its shadow visible. Colours as before.

35. No. 3. 11" 18m. L= 176°-6. Very clear and well defined. Interrupted by

clouds.

b reddish brown ; cloud in [b <?], just following central meridian, brightest.
The dark spot in the following half of c very blue ; [erf] has a mottled cloud-
like appearance.

36. No. 4. llh 59m. L = 20F-4. Very clear. Colours as before.

a consists of two belts with a rather bright line between them.

PLATE XXVII., FIGrUKES 37 to 48.

January 27, 1883.

37. llh 22m. L= 302°-7. Moderately clear. Squally ; very cold.

a very faint ; b dark brownish red, in it two white spots, one of them im-
mediately at the preceding limb. The dark spot just following the other

TKANS. ROY. DUB. SOC, N.S. VOL. IV., PABT III.

280 Bokddtcker — Observations of the Planet Jupiter,

white one, and just preceding the central meridian, decidedly and very
strikingly blue ; c d grey ; in [c d ] traces of white patches ; e more suspected
than seen.

January 30, 1883.

38. No. 1. 8h44m. L = 298°-2. Excellent,

a pale grey; b reddish brown ; [be] strikingly like white clouds on a darker
ground ; the dark spot in [b c] preceding the central meridian (not on the
meridian) decidedly blue ; in the following half of [c d~\ a small reddish spot ;
e consists of one or more streaks.

39. No. 2. 9h20m. L = 319°-8. Excellent.

The dark spot near the preceding limb in b, blue ; the long one in the fol-
lowing half of b, reddish brown ; the preceding edge of this latter spot very
white ; immediately under its preceding end (in contact with it) a small blue
spot. The darkest patch in the following half of c is blue. The markings
look most strikingly like clouds lying before each other.

40. No. 3. 10h 17m. L = 354°-3. Very good, but difficult.

s exceedingly faint, pink ; a very faint. The three small spots in c (one in
preceding and two in following half) blue.

41. No. 4. 10h 55m. L=17°-6.

s very faint, pink ; it looks, perhaps, like a cloud with a white edge lying
before the other spots. In [b c], just underneath s, a very bright, small, round
spot (Denning's white spot) ; a more distinct than before, its southern edge
rather bright.

February 2, 1883.

42. No. 1. 8h 55m. L = 38°-2. Very clear. Much detail.

In the following half of ax two faint bluish patches ; [ax a~] very bright ; a
bluish ; s pink, faint ; b brown red ; in [b c], lying on b, two very bright
clouds, especially the preceding one, is very white (Denning's white spot) ;
the dark spot in [b c] immediately under the following " shoulder" in b, and
separated from it by a white line, is blue ; c consists of separate patches ; in it,
near the following limb, a round white spot ; [erf] wider near the preceding
than near the following limb. In [e /], just following central meridian, a
very bright spot. In /two faint, darker (bluish) patches.

made at Birr Castle Observatory, Parsonstown.

281

43. No. 2. 9h 56m. L = 730,l. Very clear. Much detail. Not quite so steady as

before.

«! very faint ; [a] very white ; a bluish, with pretty sharp outlines ; s
pink, indistinct, in drawing rather too near the preceding limb ; b reddish
brown ; the two dark spots in it, as also the one in following half of c, decidedly
blue; look strikingly like white-bordered clouds with blue shadows, lying
before each other. These spots are surprisingly distinct ; d reddish ; e f bluish
grey, faint and difficult.

Febeuary 3, 1883.

44. 8h 16m. L= 1620,7. Pretty clear ; at times rather unsteady.

a indistinct at times, with very bright horizontal lines ; interrupted in its
following half ; c very decidedly reddish brown. Is the dark hook in [b c],
just following central meridian, of a bluish tinge ? The central one and
the following one of the three dark patches in c are bluish grey ; d brownish ;
d and e rather bright ; e consists of indistinct darker and brighter patches.

February 13, 1883.

45. 8b 32m. L = 286°-9. Misty, and much wind. Tube continually trembling,

so that the planet could only be seen in short glimpses. Belt a was
sketched.

a considerably changed , decidedly broken up ; two bluish-grey patches in
it on the middle of the disc, with very bright edges ; c not broken up, but a
continuous belt, much darker than d. The last belt, e, considerably darker
than last time.

March 3, 1883.

46. 7h 54m. L=39°-3. Clear.

a bluish ; s pink ; b brownish red, rather dark ; c consists of two bluish
patches with white ones preceding. These spots look like white clouds with
bluish shadows lying on the planet ; d brownish grey.

March 4, 1883.

47. 8h54m. L=225°-7. Pretty clear ; difficult, but sketch correct. Whole disc

rather pale.

a consists of very faint grey patches with bright intervals ; b reddish yellow.

282

Boeddicker — Observations of the Planet Jupiter,

In [b cj, near the preceding limb, a very bright round spot, and in its fol-
lowing half a very dark one ; c grey, partly double, interrupted by a white
spot in its following half, which, however, is not so bright as the bright spot
in [b c] ; ^and e grey, indistinct ; the central part of e somewhat darker.

March 16, 1883.

48. No. 1. 9h 37m. L = 2540,6. Image pretty steady, but not quite clear. Inter-
rupted by clouds.

Jupiter's appearance was very remarkable, especially belt b, which was in-
terrupted as in sketch. I was not quite certain whether the preceding inter-
ruption went right through, nor whether they are both white. I think there
is very light-brown shading in them. Following part of b not quite certain.

PLATE XXVIII., FIGURES 49 to 60.
March 16, 1883.

49. No. 2. 9b 58m. L=267c,2. Sketch in some respect more correct.

The first interruption does not go quite through. There is a third inter-
ruption in b, the nature of which was not quite made out.

50. No. 3. 10u 21m. L = 281°*l. Appearance strikingly as in sketch.

March 18, 1883.

61. 9h 24m. L= 1870,3. Pretty clear. Improving during sketching.-

a Hardly perceptible, a white spot in its following half ; b very brown ; in
[b c] white and dark spots ; a small, round, very white cloud immediately
preceding the central meridian. The dark spots in c perhaps slightly bluish.
Northern spots very faint ; their appearance as in sketch. Configuration of
[b c] quite correct.

March 27, 1883.

52. 9h 22m. L = 98°-6. Clear. Very difficult.

a Very faint, apparently a division in its preceding half. Near the red spot
it is very difficult, and, perhaps, somewhat doubtful. Is there a southern
continuation of b, so that b looks like a fork enclosing s ? s only perceptible
as a pink shade without distinct outline. The dark spot in [b c], on the
central meridian, bluish. In the preceding half of [b c~] one very white round

made at Birr Castle Observatory, Parsotistotvn.

283

spot, surrounded by blue shading. The small dark spot north of this white
spot is the darkest spot in c, very blue. The spots in c sometimes like clouds
lying before each other ; this, however, not very distinct ; d one darkish belt ;
its preceding half darkest. Nothing to be made out in ebut general shading ;
there are, perhaps, some darker spots in it.

Apeil 13, 1883.

53. 9h 37m. L=141o,0. Unsteady; not much detail. .Strong moonshine.

One small whitish cloud in [b c~\ on central meridian ; another in the pre-
ceding half of c. Of a nothing, of d only general shading seen.

November 13, 1883.

64. 14h 26m. L = 70°-5. Very difficult. Not very clear.

a grey, its northern edge very bright ; b reddish brown. Sometimes I
perceived something pink over the central hole, perhaps a trace of s ; c greyish ;
d consists of ill-defined dark spots. The whole north pole very much shaded.
The phase seems to be very perceptible. The dark spot in [b <?J, just on central
meridian, decidedly of a bluish tinge. At times there appeared white lines on
b, but they could not be made out properly. The shading across the hollow
in b correct ; at times rather distinct.

February 24, 1884.

65. No. 1. llh 13m. L = 338°-4. Middling.

a faint ; b brownish, division in it difficult ; c yellowish grey ; d bluish ; e
(the whole northern half) strongly shaded, bluish grey. In the preceding
half of [b c] a round white cloud.

56. No. 2. 12h 30m. L = 24°-8. Clear and steady.

a Very faint ; b difficult, very much as in sketch ; e separately visible ;
colours as before. In [b c~] three whitish patches ; in the following half of
[d e~] a white cloud.

57. No. 3. 13h 26m. L = 58°-6. Clear and steady.

a difficult, correct in general apjDearance, but uncertain in detail ; s very
faint, but unmistakable ; a and 5 perliaps too dark in drawing. Cloud in
[be], just preceding central meridian, rather white.

284

Boeddicker — Observations of the Planet Jupiter,

March 4, 1884.

58. No. 1. 8h 25m. L = 150°-5. Very clear.

There is a horizontal division in a ; b reddish. The dark spot in the
following half of c decidedly blue. The division in d more suspected than
seen.

59. No. 2. llh 29in. L = 261°-6. Clear, especially towards end of sketching.

a correct, perhaps too dark, the white intervals in it very bright ; b reddish,
difficult. The cloud in the preceding half of [b c] very bright and surpris-
ingly rounded. Hardly any, or no detail in the following half of [b <?].
d exceedingly distinct, very blue ; e separately visible.

March 10, 1884.

60 No. 1. 9h 21m. L = 6°-9. Very clear.

a very faint and indistinct, its southern edge very white ; whitish patches
in a and [a b~] ; b dark-brown red, with traces of a horizontal division ; such
traces (but more distinct) also on c and d\ c bluish, very sharply denned;
very white patches in [cc?]; e bluish grey, patchy; white spots in \_de~].
North pole slightly shaded.

PLATE XXIX., FIGrUEES 61 to 72.

March 10, 1884.

61. No. 2. llh lm. L = 67°-0. Very clear and steady.

a bluish, its southern edge very bright, slanting ; s faint. Is its southern
limb sharper than its northern one ? The region preceding and south pre-
ceding s very bright. b very distinct, brownish-red. Clouds in [b c] very
distinct, especially the central one. Bright patches in [c d~] and [de].
e seen well separated.

62. No. 3. 12h 5m. L = 106°-1. Clear, unequal.

a too dark in sketch, its shape not quite certain either, but certainly seen
separated from s ; the white spot immediately near the following end of s
very bright ; b very striking ; the horizontal divisions on it very difficult ;
clouds in [b c~] very distinct ; d and e seen separated.

made at Birr Castle Observatory, Parsonstown.

285

March 13, 1884.

63. No. 1. 9h 42m. L = 110o,4. Clear, but very unsteady. High wind.

a bluish, with a bright southern limb ; in a, just following s, a very bright
spot ; s pink, its south limb sharper than its northern one ; s decidedly
separated from a ; s lies nearer to the following shoulder of the hollow in b ;
b dark-reddish brown, the part just on the central meridian darkest. The
white spots in [b c] rather cloud-like. Is c divided lengthways ? d consists
of rather dark spots ; [c d~] and d look very much like a row of white clouds,
with dark northern shadows.

64. No. 2. llh 17ra. L = 1680,1. Misty, but steady. Constantly interrupted by

clouds.

a indistinct and uncertain ; b remarkably interrupted by bright lines, as in
sketch ; white spots in [b c~\ rather bright ; c not so reliable as b ; d very
indistinct, more a general shading off.

March 17, 1884.

65. No. 1. 9h 48m. L = 355°'5. Clear and steady. Improving.

a indistinct, patchy ; b correct, very dark, reddish brown ; c and d of an
undecided colour. North limb of c curved and irregular, as in sketch ;
d broad ; spots in [c J] like clouds ; e indistinct, but correct (two darkish
spots). Northern half of disc much shaded.

66. No. 2. 12h 18m. L = 86° -5.

a indistinct, bluish, one dark spot in it following s ; s separated from a.
This difficult to see. A white spot follows s. The preceding end of s is
darker than the whole, b is interrupted north of s, as in sketch. The pre-
ceding shoulder of the hollow in b is darkest ; the following one is not very
sharp. The hollow looks somewhat flat; is filled up with light shading.
c darker than d.

March 23, 1884.

67. No. 1. 9h 43ra. L = 174° -6. Clear, but very difficult.

a exceedingly faint ; b and c on the whole correct ; d faint ; e a general
shading. The division in d correct ; at times very conspicuous, b is red-
dish brown. The other markings are more greyish.

286 Boeddicker — Observations of the Planet Jupiter,

68. No. 2. 11* 44m. L = 2470,9. Clear. Improving.

b reddish brown ; a very bright cloud is on the central meridian ; c is
broken up, as in sketch ; d is very faint.

April 1, 1884.

69. 8h 52m. L = 56°-8. Clear, but difficult. Little detail.

a faint, with a white spot preceding s ; b dark red-brown, interrupted north
of s ; b divided lengthways ; c yellowish ; d bluish grey ; darkish spots in e.

Jupiter was again carefully examined after 10h 20m, and s was decidedly
seen well separated from a. s was followed by a brightish patch, as on former
occasions. Belt b was interrupted north of s, similarly as before. The
above seen by Lord Rosse and myself.

April 6, 1884.

70. 9h 54m. L = 1250,8. At times exceedingly clear. Enormous amount of

detail.

s and a separated ; a more distinct than usual ; no spots on s ; b very com-
plicated ; an interrujDtion in the preceding shoulder of the hollow ; c yellowish,
complicated ; central spot in it decidedly blue ; d and e unfinished, b is,
perhaps, too broad, and not quite dark enough in comparison to c.

April 7, 1884.

71. No. 1. 8h 50m. L = 2370,1. Very clear. Definition very good. Enormous

amount of detail. Sketch good.

a exceedingly faint ; b yellowish ; c bluish ; northern edge of c very
bright ; d and e as in sketch. In [b c~] three small clouds, the preceding one of
which very bright.

72. No. 2. 9h 56m. L = 277°*4. Very clear and steady.

a, as in sketch, faint; b yellowish; egrey; d bluish. The cloud in [b c] just
following central meridian very bright and well defined.

made at Birr Castle Observatory, Parsonstoivn.

287

PLATE XXX., FIGURES 73 to 84.

April 8, 1884.

73. No. 1. 9h 14ra. L = 42o,0. Exceedingly clear and steady.

South edge of a rather bright. Are there white spots in a ? b brownish
yellow ; c bluish yellow ; d bluish. In [a b~\ white clouds, c slightly too
dark, compared with b.

74. No. 2. 10h 9m. L = 75°-2. Very clear indeed.

s very faint, the dark spot immediately preceding it bluish, s was seen
decidedly separated, though this separation, especially from the following
streak, very difficult.

February 17, 1885.

75o No. 1. 12h 25m. L = 1140,5* Clear, yet Jupiter trembling, and exceedingly
difficult. Sketch not very satisfactory. Colours very pale. The dark
patch on the southern half of the disc seems to be cut up by bright
lines. The belts should be parallel to the equator, and exactly on the
middle of the disc.

76. No. 2. 13h 42m. L = 161° -3. Clear, but interrupted by clouds. Sketch
better, but not quite satisfactory. Jupiter trembling at times.
Drawing very difficult.

Colours very pale, hardly perceptible ; d bluish ; [c d~] very bright.

February 18, 1885.

77. No. 1. llh 46m. L = 249°-l. Fairly clear.

78. No. 2. 12h 51™. L = 288°'7. Very clear. Drawing very difficult.

a bluish, patchy, very faint ; b reddish brown ; d bluish ; J north edge of
c sharp and distinct ; s decidedly separated from surrounding patches ; also
of a different colour ; s reddish, or pink ; very faint. In sketch No. 1 s is
rather too dark.

* Monthly Notices of the R. A. S., vol. xliv., No. 9 (Sup.), 1884.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. III.

288

Boeddicker — Observations of the Planet Jupiter, Sfc.

March 9, 1885.

79. 12b 39m. L = 52o,0. Drawing indifferent and incomplete. Everything

only caught in short and uncertain glimpses. Definition bad, though
sky very clear.
I thought I saw s separated from a ; s pink ; a blue.

March 16, 1885.

80. 10h 20m. L = 3560,3. Clear, with interruptions. Drawing not very satis-

factory ; too much time had to be spent on it.

March 24, 1885.

81. No. 1. 12h 9m. L = 249°-9. Jupiter very poor and difficult. Drawing

indifferent and poor.
The central darkish connection between b and c of a slightly bluish shade.

82. No. 2. 13h 27m. L. = 297° -2. Better than No. 1. Very steady, but no more

to be made out.

b and c reddish.

March 6, 1886.

83. 13h 48m. Lx = 44°-l ; L2 = 540,6 * Very clear and steady. Aperture

reduced to 27 inches.

a very faint, its southern edge very bright ; d comes first in distinctness
and darkness (should be darker in sketch) ; b next, its south edge very bright ;
c darker than b, its north edge very bright. The colour of b and c is brownish
yellow, but not very conspicuous.

March 13, 1886.

84. 12* 27m. ^ = 24°-9 ; L2 = 348°'3. Clear in glimpses. Sketch not very

satisfactory ; too much time had to be spent on it.

a faint, perhaps bluish ; s exceedingly faint, pink-red ; a and s separated ;
b and c reddish yellow, especially c, which is darkest. Two very bright
and thick clouds in [i c]; d very faint indeed, perhaps too dark in sketch.
North pole much shaded, bluish grey.

* Monthly Notices of the B. A. S., vol. xlv., No. 9 (Sup.), 1885

Trans. R. Dub. S., N. S., Vol. IY.

Plate XXIV.

Otto Boeddicker del.

WUh. Hoffmann imp. Dresden.

Trans. R. Dub. S., N. S., Vol. IV.

Plate XXV

Trans. R. Dub. S., N. S., Vol. IV.

Plate XXYI.

31. 1663 Jan. 10*25

32.l86iJan.l5.in6

33 1583 Jan. 19. SW

34. 1883 Jan. 19. \(T3bm

3d. 1883 Jan. 19. Ilhl8m

.36. 1583 Jan. 19. 1 ra"

Otto Koeddickcr del.

■Willi. Hoffmanu imp. Dresden.

Trans. R. Dub. S., N. S., Vol. IV.

Plate XXVII.

Otto Boeddieker dpi.

AVilh. Hoffmann imp. Dresden.

Trans. R. Dub. S., N. S., Vol. IV.

Plate XXVIII.

49. l85^Marckl6 9h5ST

50. l583MarcK!6.IOh2r

51. IS63 March IS. 9h24T

53. 1683 April 13. 9h37"

54 1863 Nov. m4h26*

55. iWFeb.n.niy:

56 mTeb.UATW

57. 1554Feb.24.l3n261

53. IS64hcirck4. 8h25K

59. IS8^Marck4. IT29

60. 186^ March 10. 9 2\

Otto Tioeddioker del.

Wilh. Hoffmann imp. Dresden.

Tran8. R. Dub. S., N. S., Vol. IY.

Plate XXIX.

Otto Boeddicker del.

Wilh. Hoffmann imp. Dresden.

Trans. R. Dub. S., N. S., Vol. IV.

Plate XXX.

73.1584 April b.9h\f

% April S.I0h9r

is. m Feb. 17. in?

76. 1 555 Feb. 17. lb 42v

77 1685 Feb. 18. If 46'

76. 1685 Feb. 18. |f5T

79. !585Narck9. If 39"

50. 1885 March. 16. ICf 20™

81. 1685 Marck 2^.179

c52. ISS5 Marck24. 1^27

55. l686Marck.6.|W

54-. 1886 March 13. if 27"

Otto Boeddicker del.

Willi. Hoffmann imp. Drosdcn.

[ 289 ]

IV.

A NEW DETERMINATION OF THE LATITUDE OF DUNSINK OBSERVATORY.

By ARTHUR A. RAMBAUT, M.A.

[Bead November 14, 1888.]

The last determination of the latitude of Dunsink Observatory was made by
Dr. Briinnow in the winter of 1873-74. His results were published in the Fourth
Part of the Dunsink Observations and Researches, but have never been looked upon as
more than provisional, and it has always been intended that a new determination
of this quantity should be obtained whenever the Meridian Circle could be spared
for the work.

Accordingly, in November of last year, I commenced a series of observations
for this purpose on Polaris direct, and reflected from a basin of mercury. The
observations were so arranged that at each culmination of the star two reflected
observations were taken, then five direct, and then, again, three reflected.

This programme was carried out on each occasion, and in addition I obtained
two readings of the nadir point of the circle before, and two after each transit of
the star as a check on the result, although, of course, they were not necessary for
the determination of the latitude.

In the year 1886 I had made a re-examination of the screws of the four micro-
scopes on the western pier, which alone are used in observations of stars, and found
the following formulae for the corrections to be applied for their periodic errors : —

Microscope.

v. + 0"-026 cosO + 17° 45') + 0"-088 cos (2m + 74° 14').

vi. + 0 -234 cos 0 + 217 54 ) + 0 -093 cos (2u + 120 26 ).

vii. + 0-060 cos 0+ 75 30) - 0 -095 cos (2w + 0 36).

vin. - 0 -116 cos(> + 151 40) + 0 -038 cos(2w + 173 59).

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. IV.

2!)<>

Rambaut — On the Latitude of Dunsink Observatorif.

The corrections computed from these formulae are on the whole very similar to
those determined in 1875, but are generally smaller, as if the screws had worn
smooth during the eleven years which elapsed between the two determinations.

All the observations for latitude have been reduced with these values of the
periodic corrections.

The correction (x) to the circle reading, for curvature and for the inclination
of the horizontal wire of the telescope, has been computed from the following
formulae : —

x = — sin2 - ^ m sin 28 — sin (A — m) cos 8 tan / for U. C. Direct.
= + sin2 ^ fn ^ sin 28 — sin (A — m') cos 8 tan / ,, U. C. Reflected.

— + sin2

^ m^ sin 28 + sin (// — m) cos 8 tan / ,, L. C. Direct.

= — sin2 m) sin 28 + sin (ti — m') cos 8 tan / ,, L. C. Reflected.

In these equations,

8 denotes the declination of the star.

/ the inclination of the horizontal wire.

h and h' denote the eastern and western hour angles, respectively, both being,
in fact, the time of culmination minus the time of observation.

m denotes b cos <f> + k sin <£.

m' ,, — b cos <f> + k sin <f>, b and k being the level and azimuth correc-
tions, and (f> the approximate latitude of the observatory.

It will be remarked that m and m' only differ with regard to the sign of b,
which, for reflected observations, must be altered. Throughout this series of
observations, however, both m and m' have been so small that it has not been
necessary to take them into account. The second term also of the inclination,
viz., n sin 8 tan /, on account of the small values of n and/, never amounted to as
much as 0"005, and was therefore also negligible.

As the reticle of wires had been changed since the last determination of the
inclination of the horizontal wire, it became necessary to obtain a new value for
this quantity. This was derived from the observations of Polaris themselves, each
culmination supplying two series of equations — one for the direct and one for the
reflected observations — of the form,

C0 + dC= C, + x.

Rambaut — On the Latitude of Dunsink Observatory. 291

In which Cx is the circle reading when the hour angle is h (or h'),

C0 is an assumed value of the circle reading at the time of culmination of
the star, and

dC is a correction to be applied to C0 to obtain the true circle reading.
From these equations the inclination was deduced by the method of least squares,
and was found to be

/= - 190"-4.

Employing this value then to reduce the whole series, and applying the necessary
corrections for precession, nutation, and aberration, I find for the epoch 1888*0 ; —

Altitude of Polaris.

Upper Culmination. Lower Culmination.

1887. Nov. 28, 54° 40' 19"-63 1887. Dec. 11, 52° 6' 7"-51

Dec. 19, -33 ,, 18, 0 -95

„ 20, -75 „ 19, -97

„ 21, -80 ,, 20, -95

1888. Jan. 5, -70 „ 21, -83

„ 9, -57 1888. Jan. 8, -30

„ 10, '59 ,, 9, -59

„ 18, -51 „ 18, -83

„ 20, -21

23 >20 52° 6' 6"-87 ± 0"-083

54° 40' 19"-53 ± 0"-046

The mean of these results gives for the latitude of the meridian circle,

53° 23' 13"-20 ± 0"-047.

Between January 5th and 8th, the position of the telescope was reversed, the
clamp having been to the west up to then. If we separate the results before and
after reversal, we find,

With clamp west, 53° 23' 13"-34,
With clamp east, 53 23 13 -00.
2 U 2

292

Ramabut — On the Latitude of Dumink Observatory.

If we take only those days on which consecutive transits were observed, we have,
Dec. 19th, 20th, and 21st, and Jan. 8th, 9th, and 18th available. These give

1887. Dec. 19, 53° 23' 13"-15
„ 20, 13 -35

„ 21, 13 31

53 23 13 *27 with clamp west, and

1888. Jan. 8, 53° 23' 12"-94
„ 9, 13 -09

„ 18, 13 -17

53 23 13 '07 with clamp east.

The mean of these is 53° 23' 13"- 17 — a result which is practically independent of
the values of the precession and aberration adopted, as it is only necessary to
correct for the effects which they produce in an interval of 12 hours. This result
is almost identical with that obtained from the whole series, which may therefore
be taken as the latitude of the meridian circle derived from observations of Polaris.

This result is still affected by any uncertainty which may attend the constant
of refraction, and by the errors of the division lines used in the observations. The
refractions were computed from the Greenwich Refraction Tables, and any error in
the adopted value of the constant of refraction will affect the latitude by about
three quarters of the amount of the error. With regard to the division errors, the
close agreement of the results in the two positions of the instrument would seem
to show that the division errors are not very large. It is, of course, possible that
the errors on the two circles might act in the same direction, but the fact that
Dr. Briinnow's results, obtained with the same instrument and same method of
observing, differ in the opposite direction, viz. :

Clamp west, 53° 23' 13" -14,
Clamp east, 14 *08,

renders it unlikely that this is the case.

On account of this uncertainty with regard to the division errors of the circles,
I have, following Dr. Briinnow's example, computed the latitude from a number of
stars culminating at various zenith distances. These stars were not observed
directly with a view to the purpose, but in the course of my ordinary work. They
are all taken from Auwer's Fundamental Catalogue, the adopted values of their
declinations being those of the Berliner Jahrbuch. They may be divided into two

Rambaut — On the Latitude of Dunsink Observatory . 293

groups — those observed in 1887 and those observed in 1888. The following is a
complete list of them : —

1887.

P<

Date.

a

Star.

Zen. Dist.

Latitude.

Date.

S

Star.

Zen. Dist.

Latitude.

o

vv .

£ Dniconis,

OO Oft'
— O OU

S'js oo' in'
00 Lo I -

00

oepi. id.

O [1,

_L 71 0 Kft'

coo no' i a// . 1 n
00 Zo 1U V L

fx Horculis,

~r ZO oo

1 1

• fin

4- fi9 7

11 0 1

J u i , ' " 8 ■

11 H AVf 1 1 1 1 O
fX 1 1 \ 1 I 1 1 1 1 , •

4- 9*5 ^"l

T oo

1U

w

.

O J-idCtrl LaJj .

+ 1 43

1 - U 0

q -L'l ill UJII^, .

— 0 ou

1 1

Rr Qfi77

— 3 10

10 _ 0

Tulv 1

O Ul V -L O .

u Otrl pell lib p. j

-t- io

10

oU

o. AndromcdsSj

"T Z4 04

1 9 • A7
1 Z D /

8 A(.j!lllii_'. .

J_ ^ft 9ft

1 o

oepi. zo.

1 oo

19-10

i z iy

"T 110

13

■75

"fir 3077

— O 1 U

1 9 • on
1 z zu

July 22.

32 Vulpeculse,

+ 25 45

12

•76

7 Pegasi, . .

+ 38 49

12 -13

74Cygni, . .

+ 13 28

11

•57

Oct. 11.

o Andromedae,

+ 11 39

12 -84

Aug. 10.

Xj .

+ 0 13

13

•21

Oct. 14.

... fiftl 11 YY1

CO J. 1^1 llllll, .

4-47 ft

T I O

19

1Z .04

o' seq. Cygni,

+ 6 59

13

•63

o Cassiopese, .

4- 5 43

13 -16

Aug. 26.

£ Delphini, .

+ 39 10

12

•87

Oct. 24.

j3 Androruedoe,

+ 18 21

12 -14

10 Lacertae, .

+ 14 55

13

•71

v Persei, . .

+ 5 20

12 -39

k Piscium,

+ 52 44

13

•76

Nov. 18.

w Piscium,

+ 47 8

11 -80

Sept. 7.

16 Pegasi, . .

+ 27 59

11

•38

/3 Andromedae,

+ 18 21

11 -75

a Andromedas,

+ 24 55

12

•98

Mean for 1887, .

. 53" 23' 12"-44 ±

0"-ll.

1888.

Sept. 5.

w.

e Piscium,

+ 46° 5'

53° 23' 12"

•86

Sept. 12.

41 Arietis,

+ 26° 35'

53° 23' 13"-00

tj Piscium, .

38 36

13

•04

Sept. 16.

6 Piscium,

46 5

11 -74

/u Ceti, . .

43 44

13

■19

7j Piscium,

38 36

12 -11

41 Arietis,

26 35

12

24

41 Arietis,

26 35

12 -12

Sept. 7.

e Piscium,

46 5

13

07

a Ceti, . .

49 43

13 -31

7) Piscium,

38 36

13

02

Oct. 4.

e Piscium,

46 5

13 -15

/t Ceti, . .

43 44

12

77

ij Piscium,

38 36

12 -68

a Ceti, . .

49 43

13

49

o Piscium,

44 46

13 -07

Sept. 12.

e Piscium,

46 5

12

81

41 Arietis, . .

26 35

13 -50

tj Piscium,

38 36

12

46

a Ceti, . .

49 43

14 -00

a Triang.,

24 21

12

78

Mean for 1888, . . 53° 23' 12"-88 ± 0"-08.

29i

Ramraut — On the Latitude of Buns ink Observatory.

In consequence of the considerable discrepancies between these values for the
latitude, I have grouped them according to zenith distances in zones of 5° in width,
with the following result : —

Star.

Zen. Dist.

Latitude.

Star.

Zen. Dist.

Latitude.

AO CO

U — —0 .

i OKO 1 QAO

£J ! 'Li.':' '''!!", • .

- 3°

30'

53° 23' 13"

35

4-1 A vi pti q

+ 26°

35'

53° 23' 13'

'•00

- 3

30

11

32

26

35

12

•12

T!v 3077

- 3

10

13

26

t J ...

26

35

13

•50

,, ...

- 3

10

12

20

+ 26

24

12

•19

- 3

20

12

53

+ 35° — h 40°.

0" — + 5°.

/3 TlPiTinini

) J ±M1['111J11, . .

+ 39

10

12

•87

i|/ Cygni, . . .

+ 1

15

13

75

a, Pegasi,

38

46

12

•19

t'lTfyi-il

* Wo111'

o

13

13

21

y regasi, .

38

49

12

•13

•J IJAVvl l <X j ■ •

1

43

12

53

II JL 1 ' Li till . . , ,

38

36

13

•04

+ 1

4

13

16

j , ...

38

36

13

■02

4. fi° Lift3

j, ...

38

36

12

•46

o' Seq Cygni, . .

+ 6

59

13

63

...

38

36

12

•11

o Cassiopese, . .

5

43

13

16

38

36

12

■68

v Persei, . . .

5

20

12

39

+ 38

43

12

•56

+ 6

1

13

06

+ 40° - + 45°.

+ 10° - + 15°.

fi Ceti, ....

+ 43

44

13

•19

74 Cygni, . . .

+ 13

28

11

57

j j

43

44

12

•77

10 Lacerte, . .

14

55

13

71

o Piscium, .

1

44

46

13

•07

o Andromeda?,

11

39

12

84

+ 44

5

13

■01

+ 45° -"+ 50°.

+ 15° - + 20°.

4 13

21

12

71

6 Serpentis p.,
w Piscium, .

+ 49
47

18

8

13
12

■30
•34

/8 Andromedae,

4- 10

ZL

1 L

1 A

47

8

11

•80

+ 18

21

11

75

6 Piscium, . .

46

5

12

■86

+ 18

21

11

19

46

5

13

•07

+ 20° - + 25°.

,, ...

46

5

12

•81

o Andromedae,

+ 24

55

12

98

,, ...

46

5

11

•74

> > •

24

55

12

67

, , ...

46

5

13

•15

a Triang., . . .

24

21

12

78

o Ceti, . . .

49

43

13

•49

+ 25° - + 30°.

+ 24

44

12

81

49

43

13

•31

Herculis, . .
>j •

+ 25

35

11

60

49

43

14

•00

25

35

10

•88

+ 50° - + 55°.

+ 47

33

12

•90

32 Vulpeculae, . .

25

45

12

•76

S Aquilae, . . .

+ 50

28

13

•79

16 Pegasi, . . .

27

59

11

•38

k Piscium, . . .

52

44

13

•76

41 Arietis, . .

26

35

12

•24

+ 51

36

13

.77

Rambaut — On the Latitude of Dumink Observatory .

295

I have here omitted the observations of Sept. 16th, 1887, as they were made
under very unfavourable circumstances.

An inspection of these figures shows that the observed values of the latitude
diminish pretty steadily down to about 20° or 30° zenith distance, and from this
point they begin to increase again. I have therefore supposed the discrepancies
to be due to the flexure of the instrument, and attempted to represent it by an
expression of the form of

/ sin z + g cos z,

so that each of the means given above supplies us with an equation of the form

A<j) + fsmzl+g cos zx = <j>x — <f>0 = nh

in which <f)X is the observed, and <f>0 the adopted value of the latitude, and A<£
the correction to the latter, while zx is the zenith distance. I have taken
<f>0 = 53° 23' 13"'00, and weighting the equations according to the number of
observations upon which each depends, I find

A(/> = + 5"-64,
f = -2 -39,
y = - 5 -86.

These values being quite inadmissible, this result shows that the discrepancies
between the different means is not due to a flexure error of the form given above,
nor are the observations numerous or accurate enough to attempt a determination
of the terms containing higher multiples of z.

This being the case, it apjDearecl to me that it would be of interest to compare
the mean of the results for the stars of south zenith distance observed in 1888, with
the result obtained from the direct observations of Polaris combined with the nadir
point of the circle, the mean zenith distance of the former being almost the same
as that of Polaris.

For this purpose I have to reject the observations of Polaris on Dec. 11th and
on Jan. 20th, as on neither occasion were the observations of the nadir-point satis-
factory. I thus obtain from the other observations : —

Altitude of Polaris at Upper Culmination.

Direct. Reflected. Direct. Reflected.

1887. N/ov. 28, 54° 40' 19"-04 54° 40' 20"-22. 1888. Jan. 9, 54° 40' 19"-99 54° 40' 19"-15.
Dec. 19, 18 -83 19 -83. ,, 10, 19 -91 19 -28.

,, 20, 19 -18 20 -32. ,, 18, 18 -95 20 -07.

„ 21, 19 -80 19 -80. ,, 23, 19 -07 19 "33.

1888. Jan. 5, 19 -69 19 -70.

296

Rambaut — On the Latitude of Dunsink Observatory .

Altitude of Polaris at Lower Culmination.

1887. Dec. 18,
„ 19,
„ 20,
.. 21,

We thus obtain,

Direct. Reflected.

52° 6' 6"- 16 52° 6' 7"'73.

6 "26 7 -67.

6 -64 7 -26.

6 -20 7 -46.

1888. Jan. 8,
„ 9,
18,

Direct.
52° 6' 6"-94
6 -71
6 -69

Reflected.
52° 6' 5"-67.
6 -48.
6 -96.

CI. W.

CI. E.

( U. C.
(L. C.

( u. c.

L. C.

Direct.

54° 40' 19"-31
52 6 6 -31

54 40 19 -48
52 6 6 -78

Reflected.

54° 40' 19"-99
52 6 7 -5-3

54 40 19 -46

52 6 6 -27

And for the different values of the latitude —

Direct.

53° 23' 12"-81
13 -13

Reflected.

53° 23' 13"-76
12 -87

Clamp W.,
Clamp E.,

We thus see that the value of the latitude derived from the direct observations of
Polaris, with clamp west, is almost identical with that derived from the southern stars
of nearly the same mean zenith distance, and in the same position of the instrument —
the seconds, in the former case being 12"-81, and in the latter 12"-88. This would
lead us to sujjpose that the flexure was exceedingly small, and a comparison of the
results derived from direct and the reflected observations of Polaris, in the two
positions of the instrument, would lead to the same conclusion.
Which of these various results shall we adopt ?

It appears to me that the mean of the result derived from the whole series of
observations of Polaris, and that derived from the observations of the Berliner
Jahrbuch stars, will probably give us the best value of the latitude — the former
being free from flexure, but affected by division errors, and the latter practically
free from division errors, but still affected by flexure and any errors which may
exist in the adopted declination of the stars.

The mean of these results, weighting them according to the number of observa-
tions upon which each depends, is

53° 23' 13"-08 ± 0"-04.

Dropping the second decimal, therefore, I conclude that until the division errors
of the individual lines on the circles have been determined, as accurate a value of
the latitude of the meridian circle as can be hoped for, is

53° 23' 13"-1.

[ 297 ]

V.

A REVISION OF THE BRITISH ACTINIiE. PART I. By ALFRED C.
HADDON, M. A. (Cantab.), M.R.I.A., Professor of Zoology, Royal College of Science,
Dublin. Plates XXXI. to XXXVII.

[Eead June 13, 1888.]

This is the first of what I hope will be a series of communications to the Royal
Dublin Society on the Sea Anemones of the British seas. Thanks to the labours
of such naturalists as Mr. George Johnston, Professor Edward Forbes, Sir John
Dalyell, Mr. R. Q. Couch, and many others, but most especially to those of
Mr. P. H. Gosse, we have a very complete knowledge of the appearance and
habits of the Actiniae found round our shores. In scarcely any country is the
Actinian fauna so well described and figured as that in our own.

In classifying the Actiniae external characters were alone formerly considered ;
but of recent years attention has been drawn to internal structure as a basis for
classification. It is to the brothers Hertwig that the credit of the new departure
is mainly due, and more particularly to Dr. Richard Hertwig, who, in his masterly
" Report on the Actiniaria" dredged by H. M. S. "Challenger," has laid down
broad lines of Actinian taxonomy, which, being based on morphology, are more
strictly scientific than the systems of Prof. H. Milne Edwards, Mr. Gosse,
Prof. Verrill, or Dr. Andres.

The time has now arrived when it is advisable and possible to revise the
British Actiniae. Not a few of the genera and species found around the coasts of
Europe have been described from British specimens ; but, apart from external
characters, we are unable to assign to most of them a position in the groups
proposed by Prof. R. Hertwig, on account of the absence of any knowledge of
their anatomy. It is to take away this reproach that I have attempted a revision
of the British Actiniae, of which the present is a first contribution.

Considerable confusion has unnecessarily been made in the synonymy of the
Actiniae, owing to the generally recognised rules of zoological nomenclature being
too often ignored. In the course of this revision I have found it necessary to

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART V, 2 X

298

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adopt several generic and specific names, which have been rarely used by-
zoologists, in the place of very well-known names — for example, Tealia crassicornis
(0. F. Mull.) becomes ' Urticina felina (Linn.), and Sagartia (Ileliactis) bellis (Ellis
and Sol.) must bo known as Cereus pedunculatus (Pcnn). I have done this with
great reluctance, as it is not easy to remember the scientific names of animals
when they are being continually changed; and, further, superfluous change in
nomenclature is very objectionable from a faunistic and museum point of view;
the latter, however, need hardly be considered in the present instance, as few
museums possess any Actinise at all.

Not only has simple priority been ignored, but new names have sometimes
been given, even when the introducer of the new name was aware of the pre-
existing names.

In a few instances an old name has been misapplied to a species when the recorder
had no knowledge that it was the same species. This error has occasionally been
fallen into because the published description of the older naturalists were usually
somewhat vague, so that the description might very well apply to more than one
species. It is only by the recovery of the lost type and its re-description that
such unavoidable errors can be rectified. But again, confusion is made when a
zoologist assumes, without sufficient proof, that his specimen, possibly only known
in the preserved state, is the same species as that previously described from living
forms, captured, perhaps, thousands of miles distant. This action, instead of
having the desired effect of simplifying classification, adds to its confusion, as it
is always much easier to unite species together than to split up a species. If any
doubt exists it is far better to describe the species as new, and to leave its
amalgamation with previously described species to one who has a personal
knowledge of that species, than to beg the question, and, by assuming an
identity, to run the risk of giving false anatomical characters to an old species.

When an author has diagnosed a new genus, and named a species as its type,
these names should thenceforth be inseparably connected, unless priority has
been infringed. It is the ignoring of this recognised rule which has largely
complicated Actinian nomenclature.

For the mere naming of sjDecimens, a trained eye, an acquaintance with the
bibliography, and an appreciation of the rules for zoological nomenclature, are
alone necessary. For the classification of the genera and species it is requisite to
have a fairly minute knowledge of their anatomy. Mere reliance upon outward
form or external characters has led to essentially dissimilar forms being associated
together. A rational scheme of classification must also take the development of the
individual into account. Thus, while the name of an animal may be determined
by the collector or museum curator, these must accept the classification suggested
by the comparative anatomist and embryologist. Once the taxonomy is

Haddon — A Revision of the British Actiniae.

299

established, the most easily ascertained characters, even if they are of trivial
importance, are all that are necessary for determining purposes. The separation
of the methods of systematic zoologists and those of structural zoologists has been
the fruitful cause of complication in nomenclature.

In the following descriptions I have to classify the Actiniae referred to from an
anatomical standpoint ; but, at the same time, external characters of both living
and preserved specimens have not been ignored. Preserved Actinias are peculiarly
difficult to determine : with increased knowledge a great deal may be done, but in
many cases the task will probably always remain hopeless, unless notes on form
and colour have been taken of the living animal.

In the following pages it will be seen that the species of the genera Edwardsia
and Halcampa, which have already been examined, can readily be distinguished
by certain anatomical details, as, for instance, the pattern of the longitudinal
retractor muscles of their mesenteries. On the other hand, the three species of
the genus Sagartia, s.s. — S. miniata, S. venusta, and JS. nivea, cannot at present be
distinguished anatomically. A possible explanation is not far to seek. From
their general structure we may confidently assert that Edwardsia and Halcampa
are old genera, as they retain, in their adult state, features which are transiently
present in the young of the more typical Actiniae. We may therefore assume
that the existing sjDecies of this genera are well established, and have remained
constant for a sufficient period for the acquisition of definite structural characters.
The genus Sagartia is more specialized, and it is open to us to suppose that the
species have not yet got beyond the stage of colour differentiation.

Parallel cases can be found in almost every group of animals where the
species of one genus are easily defined, whereas in another genus the specific
distinctions have reference to the presence or absence of a particular spot or
marking.

In order to establish actinological studies on a sure foundation it will be
necessary first of all to recover the types. The most satisfactory way to
accomplish this is to go to the original locality and collect specimens there.
Then, having recovered it, the type must be subjected to anatomical investigation.
Its place in the system of Actiniae will then be accurately known, and not till then.
There has been up to the present a great deal too much of guess-work in this
group.

I have found it necessary to introduce a few new terms, in order to indicate
certain mesenteries and the chambers between them. In adult forms an axial line
is always recognisable, but beyond that, in the majority of Actiniae there is a
radial symmetry. It has long been known that the larval forms of all Actiniae
hitherto studied are bilaterally and not radially symmetrical, and a definite
orientation is possible for these, and for some adults, as I shall subsequently

2X2

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Haddon — A Revision of the British Actinice.

show. The new terms I propose have relation to this primitive bilateral
symmetry.

I have shown elsewhere (1887, p. 473*) that the larval Halcampa possesses a single
deep oesophageal groove. I have reason to believe that the remarkable groove
in Peachia occurs at the same angle of the oesophagus in that genus. The single
oesophageal groove of the Zoantheae has the same relations. I therefore take this
as the more important groove, and speak of it as the " sulcus :" the less important
opposite groove is the " sulculus."

The sagittal oesophageal grooves were named by Mr. Gosse the " gonidial
grooves " {canales gonidiales) (1860, p. 4). He did not distinguish between them.
Dr. Andres (1884, p. 73) adopts the terms gonidium and gonidulum. ' It may be
considered that it is unnecessary to coin new terms with these before us ; but they
do not readily lend themselves to combination with others. The brothers
Hertwig distinguished these grooves as "dorsal" and "ventral." This is an
unfortunate application of terms which have a false significance in our group.
We may speak of organs as "lateral" to a given axial line, but the words
"dorsal" and "ventral" have no meaning, except a misleading one, for the
Actiniae. The sulcar directive mesenteries correspond with the "ventral" of
the German authors, and the sulcular with the dorsal. Dr. Hickson (1883, p. 693)
has introduced the term " siphonoglyphe " for the ciliated axial groove of
Alcyonarians, in which group it is now universally accepted. It is, however,
not conveniently applicable to the Actiniae. The terms " axial " and " abaxial,"
as used by Prof. A. Milnes Marshall (1883, p. 125), for Pennatula, have express
relation to the axis of the polypdom, as Dr. Marshall speaks of the "inner or
axial," and the "outer or abaxial," surfaces. These terms are clearly unsuitable
for Actiniae.

In adult Actiniae with two oesophageal grooves it is not possible to distinguish
which is the sulcar and which is the sulcular groove ; nor when only one groove is
present can we in all cases determine which it is. Probably it will be found that,
in every case where one groove only is present during the whole of life, it is the
sulcar groove. But in the case of the genus Sagartia (Gosse, s. s.), one groove is
as often present as two. There is no reason, as far as is known, to regard this as
the sulcus. It appears to be more probable that the one-grooved condition is a
secondary feature, and the groove may be either the sulcus or the sulculus.
When it is impossible to determine the homology of the groove or grooves, I shall
simply term them oesophageal grooves.

* In referring to the bibliography which is appended to this Bevision, I have adopted the plan
introduced by Dr. E. L. Mark, of Harvard, by which the reference number gives the reader the
approximate date of the article.

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301

In addition to the sagittal grooves lateral furrows may or may not be present ;
they are of no morphological importance.

The whole endodermal cavity has been appropriately termed the ccelenteron ;
it is divided radially by the mesenteries into chambers. I have adopted Mr.
Fowler's (1885, p. 578) terms of "endoccele" for an intra-mesenterial chamber,
and " exoccele" for an inter-mesenterial chamber. The endocceles of the directive
mesenteries are respectively the sulcar endocoele and the sulcular endoccele. The
combinations used to designate the various chambers of the ground-type are given
in the last section of this communication.

The use of the term " septa" instead of " mesenteries" for the radial partitions
of the ccelenteron is to be strongly deprecated, owing to the universal acceptance
of that word for the radial calcareous plates of the Madreporaria.

Mr. Bourne's (1887, p. 311) term, " niesoglcea," bids fair to be generally
adopted. It conveniently replaces the term " mesoderm," which is open to serious
objection, and such cumbersome names as " supporting membrane" or the like.

A word of personal explanation is necessary. I had hoped to be able to deal with
the subject in something approaching to a logical method; but two circumstances
have prevented this : the first is the difficulty which exists in procuring specimens
of many of the species. If completed work on available specimens was retarded
in publication until other species or genera were obtained, the results attained
would long lie dormant. In the second place, I am leaving Ireland for some time,
and it may be a considerable period before I shall be able to conclude this series
of Papers. I shall not even have the opportunity of reading the proofs of this
Memoir. Thus, at present, I am only in a position to give an approximately
complete account of one group of the Actiniae — the Chondractininae ; in another
section of this Paper I deal with a variety of genera, all of which, however, may
be regarded as more or less representing the various stages in the evolution of the
typical hexameral Actinia?.

The family Sagartidse was first thus defined by Mr. Gosse (1858, p. 415):
" Sagartiadse [this is the form of spelling adopted, and adhered to, by Mr. Gosse].
Basis adhserens. Tentacula simplicia, in cyclis continuis digesta. Cutis, pro filis
retractilibus armatis emittendis, perforata." It included the genera Actinoloba
(4. dianthus) and Sagartia, the latter being thus diagnosed : " Basis integra, cyclica.
Tentacula libenter et totaliter retractilia. Cutis acetabulis instructa. Os duabis
canalibus gonidialibus instructum" with the following species: S. bellis, S. miniata,
S. rosea, S. omata, S. ichthyostoma, S. venusta, JS. nivea, 8. sphyrodeta, 8. pallida, S.pel-
lucida, S. coccinea, S. troglodytes, S. viduata, S. parasitica. Although the title-page
of the " Actinologia Britannica" bears the date of 1860, the book was issued in
bi-monthly parts, of which the first (pp. 1-32) was issued, as dated, on March 1st,
1858; consequently the fuller diagnosis, in English, of the family Sagartiadas is

302

Haddon — A Revision of the British Actinice.

practically synchronous with the former. Five British genera are recognized,
viz. : Actinoloba, Sagartia, Phcllia, Adamsia, and Gregoria. The foreign genus,
Discosoma, is also added to this family. The species of Sagartia are treated in
the above order. On p. 122 of his monograph (published Sept. 1, 1858), Mr. Gosse
remarks : " The species already described appear to me to be divisible into four or
five groups . . . The most typical group, and that for which, should the genus
be broken up, I would retain the name Sagartia, includes the following species : —
miniata, rosea, ornata, ichthyostoma, coccinea, venusta, nivea ... A group rather less
typical than this, I consider to be formed by the following species : — sphyrodeta,
pallida, pura . . . Should a generic name ever be required for this group, I
propose for it that of Thoe : troglodytes, viduata, and parasitica may be associated
as a group departing still more widely from the typical form ... In the event
of redistribution, this group might receive the name of Cylista : bellis will
probably be considered by many as worthy of generic separation ... It might
be called Scyphia. About the same date Mr. Wm. Thompson (1858), being struck
by the peculiar characters of S. bellis, created for it the genus Heliactis. Both
Messrs. Gosse and Thompson overlooked the fact that Dr. Oken (1815, p. 349)
erected the genus Cereus, constituting C. bellis as its type. Profs. Milne Edwards
(1857, p. 269) and Verrill (1869, p. 480), and M. Fischer (1874, p. 211), appear to be
the only authors who have recognized Oken's priority ; although the first does not
actually allude to Oken. Again, M. Fischer correctly restores Mr. Pennant's
(1776) specific name, pedunculatus (not u pedoriculatus," as M. Fischer spells it),
instead of the more commonly adopted bellis of Ellis and Solander (1786).

From the foregoing abstract it will be perfectly evident that Mr. Gosse
regarded S. miniata as the type species of his genus Sagartia. For the future
these two names must remain inseparable.

Mr. Gosse makes the possession of two oesophageal grooves one of the
characters of the genus, and they are certainly very commonly present amongst
the Sagartidse. Mr. G. Y. Dixon has, however, very recently shown (1888, p. 120)
that one oesophageal groove only is as frequently found as two in both S. miniata
and S. venusta. Of this I have also satisfied myself. My friend and pupil,
Mr. Francis Dixon, is at present investigating the anatomy of these and allied
species, and he has found (1888) that only one pair of directive mesenteries are
present in those forms in which the single oesophageal groove occurs, and that in
adult specimens the number of paired mesenteries does not appear to bear a direct
ratio to the number six. In all cases, amongst adults, more than six pairs of
perfect mesenteries are present.

I find that in a specimen of Cereus pedunculatus [Sagartia bellis, Auct), of which
I have a series of sections, there are two oesophageal grooves and two pairs of
directives : the first two cycles of mesenteries (i. e. twelve pairs) are perfect, and

Haddon— A Revision of the British Actiniw. 303

in addition an irregular number of the other mesenteries may also reach the
oesophagus. The same occurs in Cylista viduata; but in Cylista undata (Sagartia
troglodytes) no more than twelve pairs of primary mesenteries, including two pairs
of directives, join the oesophagus in the single specimen of which I have sections
(M. Fischer (1874) regards C. troglodytes as a variety of C. viduata). In Gephyra
dohrnii the second cycle of mesenteries extends to the greater portion of the
oesophagus, if not to its whole length. Here again two oesophageal grooves
and two pairs of directive mesenteries are present in the specimens I have
investigated.

Prof. Verrill (1869, p. 477) accepts Mr. Gosse's group, but regards the
"Sagartinse" as a sub-family of the Actinidse (see also Verrill, 1864, p. 21 — Proc.
Essex Inst., v. 1868, p. 322 — ibid, vi. 1869), including within it Metridium, Oken
(type M. dianthus) ; Cereus, Oken (type C. bellis (pedunctdatus) ; Calliactis, Verrill,
gen. nov. (type C decorata, Drayton sp.); and Sagartia. Concerning this genus
Prof. Verrill says (/. c. p. 483): "It seems necessary to restrict this genus to the
group considered typical by Gosse, with which the rather less typical group, to
which he gives the subgeneric name Thoe, and some other forms may also be
united ; Nemactis (type N. primula — Drayton, sp. )

Dr. Andres(1884, pp. 130-132) includes Actinoloba, Heliactis, Cylista, Adamsia,
Aiptasia, Sagartia, and Nemactis in the Sagartidse, thus excluding the genera
Phellia and Gregoria. Nothing can be said about the latter until it has been
re-discovered ; it was described from a single, possibly immature, specimen. In
addition to Nemactis, which Prof. Verril had previously recognized as belonging
to this group, Dr. Andres adds Aiptasia (type A. couchii — Gosse).

Prof. E. Hertwig (1882), in his most valuable Report, says: — "I have followed
Gosse as far as possible in fixing the limits of the families, but my great
endeavour has been to define more sharply the meaningless characteristics hitherto
in use, by bringing more emphatically forward the anatomical characteristics
predominantly developed in the separate families, such, for example, as the nature
of the septa [mesenteries], and of the circular muscle, the presence of secondary
tentacles and acontia (the latter may appropriately replace the cinclides), and the
distribution of the reproductive organs. Thus I have characterized the family of
the Sagartidae afresh, as I have laid down as essential that they should possess
acontia and a mesodermal circular muscle, and that the six pairs of principal septa
[mesenteries] should be distinguished from the rest by being alone perfect, and
not bearing reproductive organs. I found these conditions in a whole series of
forms belonging to the Sagartiaa ; and if other species hitherto placed among them
do not agree in these respects, it is impossible that they should remain in one and
the same family" (p. 18).

The family Sagartidae is succinctly denned (p. 70). The presence of acontia

304 Haddon — A Revision of the British Actinia?.

and of but six pairs of perfect and at the same time sterile mesenteries is made of
prime importance. The brothers Hertwig first observed these facts in Adamsia
diaphana, Metridium dianthus, and Calliactis [Sagartia) parasitica. The same
occurred in five different species of the "Challenger" material, viz. Sagartia, sp.
(p. 72), Calliactis polypus (Forsk.) (p. 74), Cereus spinosus, n. sp. (p. 76), Phellia
pectinata, n. sp. (p. 81), Bunodes minuta, n. sp. (p. 84).

Prof. Hertwig evidently had some misgiving in including the genus Bunodes
amongst the Sagartidie. On page 84 I. c. he says : "Among the ' Challenger' material
I found one true representative of the Sagartidae, the external appearance of which
justified its being placed in the genus Bunodes. I have determined it as Bunodes
minuta, as I consider it quite possible that the acontia have hitherto been
overlooked in the species of the genus Bunodes. If this view be erroneous it
would be necessary to erect a new genus for Bunodes minuta and Bunodes coronata."
It has evidently escaped Prof. Hertwig's notice that M. Fischer had already, in
1874, proposed a new genus, Chitonactis, for the reception of Bunodes coronata,
Gosse. These two species will be referred to later on.

It is unfortunate that Dr. Hertwig has laid down the law so strongly as he has,
as he leaves himself no loophole for escape. We have just seen that Sagartia
miniata, Gosse (1853) (perhaps it should more correctly be designated S. elegans
(Dal.) (Sir J. Dalyell — 1848, p. 225, pi. xlvii., figs. 9-11), is the type species of the
genus, S. venusta being a closely allied species. As previously stated, Mr. Francis
Dixon's discovery concerning the irregular occurrence of the mesenteries precludes
the drawing of a hard-and-fast line, as has been done by Prof. Hertwig. If we
follow this anatomist we shall be landed in the difficulty of excluding the genus
Sagartia from the family Sagartidas !

It appears to me that we have not at present sufficient facts to be able to
satisfactorily classify many of the Sagartians. By the latter term I include all
those Actiniae which possess acontia. There is, however, a natural group amongst
them which, for the present, I will assume has the value of a sub-family, and
which I propose to term the 11 Chondractininse."

Chondractininse. — New sub-family of Sagartian Actinias, with the lower por-
tion of the column more or less rigid, upper portion (capitulum) usually different
in character from the lower (scapus), and capable of being entirely invected ;
strong mesodermal circular muscle ; numerous contractile tentacles ; the primary
mesenteries, consisting of two pairs of directives and four pairs of ordinary
mesenteries, only are perfect and at the same time are sterile ; a cuticle is always
more or less developed, except upon the capitulum ; warts or nodules are generally
present ; the acontia, which always occur, are rarely emitted, and then by the
mouth only.

It will be seen that this definition is almost the equivalent of that of Prof.

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305

Hertwig's family Sagartidae, but for the reasons given above this family cannot
stand. The proposed sub-family is more extensive than the sub-families Phellinae of
Prof. Verrill, or Phellidae of Dr. Andres. Although Phellia is probably allied to this
group of Actiniae, I have considered it wiser to propose a new name, partly because
we have not sufficient anatomical investigation on Phellia, and partly on account
of the more extended range which I desire to give to this sub-division, the older
terms being subject to misapprehension.

CHONDRACTININiE.

Chondractinia, Liitken, Type C. digitata (0. F. Miiller).
Hormathia, Gosse, ,, H. margaritce, Gosse.
Chitonactis, Fischer, C. coronata (Gosse).

Actinauge, Verrill, ,, A. richardi (Marion).
Paraphellia, n. g., ,, P. expansa, Haddon.

Chondractinia, Liitken, 1860.

Chondractininae with thick mesoglcea which prevents the body from being
much contracted ; circular muscle very large ; capitulum smooth (usually) ;
summit of scapus surmounted by twelve tubercles (coronal tubercles) ; scapus
more or less warty or nodular; cuticle feebly or strongly developed.

The genus Chondractinia was established by Dr. Liitken (1860, p. 190), for
Actinia digitata, Miiller, and A. nodosa, Fabr., but without any definition. The
name appears to have entirely lapsed, and has only twice since been used — in
1875, by Dr. Liitken, and by Canon Norman in the following year in referring to
C. nodosa. The genus is very close to Hormathia, Gosse, and they may possibly
be merged in future.

Mr. Gosse included A. digitata, Miiller, in the genus Tealia, which latter he
had proposed for Urticina felina (A. ci^assicomis, Muller). As this was done without
a personal knowledge of the species, but merely from the drawings and description
of Mr. Joshua Alder, we may assume that he would have acquiesced in their
generic distinctness had he then been acquainted with it. Urticina has priority
for the generic name of A. felina, Linn. It is open to us either to keep Tealia for

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Haddon — A Revision of the British Ac Unite.

A. digitata, or to drop that generic title altogether, and adopt instead the slightly
later, Chondractinia of Dr. Liitken, although the latter was never strictly denned.
The objection to retaining the name Tealia is, that it has always been more par-
ticularly associated with its type species crassicornis, but the latter belongs to an
entirely different family of the Actiniae from that in which A. digitata can be
placed.

RECOGNISED SPECIES OF THE GENUS CHONDRACTINIA.

Chondractinia digitata (0. F. Muller).
North European Seas.

Chondractinia nodosa (Fabricius).

This is not, however, the Actinauge ( Urticina) nodosa of Prof. Verrill.
Greenland Seas.

Chondractinia digitata (0. F. Muller).
(Plates xxxii., figs. 7—10 ; xxxm., figs. 11, 12; xxxv., figs. 5—7.)

Actinia digitata, n. sp., 0. F. Muller,
Actinia digitata, 0. F. Muller,
Actinia digitata, Sars,
Cereus digitata, Milne Edwards,
Tealia digitata, Gosse,

Tealia digitata, Norman,
Urticina digitata, Verrill, .
Chondractinia digitata, Liitken,
Tealia digitata, Andres,

1776, Zool. dan. prodr., No. 2796.
1806, Zool. dan., v., p. 16, pi. cxxxiii.
1851, Nyt. Mag. Naturvid. vi., p. 143.

1857, Hist. Nat. des Cor., L, p. 272.

1858, Ann. Mag. Nat. Hist. (3), L
p. 206, pi. vi., fig. 10.

1868, Shetland Report, Brit. Assoc.
1873, Amer. Jour. Sci., vi., p. 5.
1860, Vidensk. Meddel. Nat. Foren
1884, Le Attinie, p. 203.

p. 417 ; and Actin. Brit.,

p. 318.

188.

The above are the most important references to this species. A more complete
bibliography is given by Prof. Andres. Since the time when Muller described the
species, Messrs. Sars, Alder, Gosse, and Liitken, have alone added to our know-
ledge of it. Dr. Liitken describes it as being " in general white, sometimes pale
flesh-coloured, especially above nearest the origin of the tentacles, which also have
a faint reddish colour. It is of a firm, cartilaginous consistency, and can change
its form very little. Its tolerably smooth base widely spreads to embrace shells
of living Buccinum or Tritonium ; rugged transverse eminences appear in rows on
the base ; the sides are also beset with oblong knobs which are arranged fairly
regularly ; at its upper portion they are suddenly larger, and again decreasing in

Haddon — A Revision of the British Actinice.

307

magnitude, they arrange themselves in twelve rows converging to the mouth.
Some examples are, moreover, more tuberculated than others, and in some solitary
cases can even be seen almost entirely smooth." Dr. Liitken never saw it "fully
expanded, as represented in the 1 Zoologia Danica,' but either with entirely with-
drawn tentacles, or when only little could be seen."

A good figure of this species has long been a desideratum. Owing to the
great kindness and liberality of my veteran friend and colleague, Mr. Gosse, in
placing all his drawings and sketches of Actiniae at my disposal, I am enabled to
reproduce two of his beautiful drawings (PI. xxxn., figs. 7 & 8). The drawing was
labelled " Tealia digitata, from Mr. Stanger's specimen, del. P. H. G., June 11,
1860." Canon A. M. Norman has, with characteristic generosity, given me two
specimens of this species which he dredged from the Shetland Seas in 1863.
These I have drawn on PI. xxxm., figs. 11 & 12. At the same time he forwarded to
me the original drawing of the same species by Mr. Joshua Alder ; and although the
same drawing was copied in Mr. Gosse's ' Actinologia Britannica' (PI. vi., fig. 10),
I have not considered it superfluous to reproduce it once more. On comparing the
two reproductions it will be seen that Mr. Gosse's artist has made the tubercles
nearly uniform in size, whereas the coronal tubercles should be large and distinct,
as Mr. Gosse quotes from Mr. Alder (I. c. p. 206). The capitular tubercles have
been rendered too prominent in Mr. Alder's drawing. In neither Mr. Gosse's
specimen nor in those I have examined are there any tubercles on the capitulum.
It would be ungracious to assume an error of observation on the part of such an
accurate observer as the late Mr. Alder, so, for the present, I prefer to leave the
presence of small tubercles on the capitulum of this species an open question.
Lastly, the colour of the figure in Mr. Gosse's plate agrees neither with Mr. Gosse's
own. description (/. c. p. 206) nor with Mr. Alder's drawing.

From Mr. Gosse's drawing it appears that the colour of this species may be
pinkish white and the tentacles violet. With the four coloured figures of living
specimens of C. digitata (PI. xxxn.) and the two representations of preserved forms
(PI. xxxm.) there should now be no difficulty in its identification.

I have submitted half of the specimen drawn in fig. 12, PI. xxxm., to an
anatomical investigation. A vertical section through the animal (PI. xxxv., fig. 7)
shows the great size of the mesoglceal sphincter or circular muscle (cm.). By
transverse sections (PI. xxxv., figs. 5 & 6) we find that the mesoglcea is relatively
very thick. This is especially noticeable in the mesenteries, where it is thicker
than in any other Actinian with which I am acquainted : the lacunae, which are
shown in fig. 5, from the irregularity of their appearance, appear to be simply due
to some imperfection in the method of preparation. The character of the
longitudinal or retractor muscles of the mesenteries is very characteristic (fig. 6),
The specimen is a male.

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H addon — A Be vision of the British Actinice.

Chondractinia nodosa (Fabr.).
(Plates xxxiii., fig. 13; xxxv., fig. 4.)

Actinict nodosa, n. sp., 0. Fabricius, .
Actinia nodosa, Gmelin,
Actinoloba nodosa, Blainville,
Actinoloba nodosa, Blainville,
Actinia nodosa, Brandt,

Metridium (?) nodosa, Milne Edwards,
Chondractinia nodosa, Liitken, .
Actinia nodosa, Mobius,

Chondractinia nodosa, Liitken,
Chondractinia nodosa, Norman,
Actinia nodosa, Andres,

1780, Fauna Gronlandica, p. 350.
1788-93, Syst. Nat. (Linn.), xiii., p. 3133.
1830, Diet. Sci. Nat., lx., p. 288.

1834, Manuel d'Actin. et de Zooph., p. 322.

1835, Prod. Descript. Animal, p. 10 (also Ann. Sci. Nat. (2)

v., 1836).

1857, Hist. Nat. des Cor., &c, i., p. 254.

1860, Vidensk. Meddel. Nat. Foren. Kjobenbavn, p. 190.

1873, Jabresb. Com. Untersucb. Deutscben Meere in Kiel.,

p. 246 (abstr. Ann. Mag. Nat. Hist. (4), xiii., 1874,

p. 203.

1875, Arctic Manual and Instructions, p. 186.

1876, Proc. Eoy. Soc, xxv., p. 208.
1884, Le Attinie, p. 378.

The typical form of Urticina or Actinauge nodosa of Prof. Verrill and other
American authors is not this species ; its identity is discussed further on. It is,
however, possible that some of the forms identified under this name may really be
this species.

Although this species has not yet occurred within the British marine area, I
have deemed it advisable to introduce a description of it for the sake of comparison
with C. cligitata. The accompanying figure (PI. xxxm., fig. 13) is the only published
drawing of it. For the loan of the specimen from which the drawing was made I
am indebted to the kindness of Canon A. M. Norman. The specimen was named
by Dr. Liitken, and is therefore authentic. It was obtained from the west coast
of Greenland, off Disco Island (lat. 69° 31' N., long. 56° 1' W.), from 100 fathoms,
July 23, 1875, in the "Valorous" expedition.

Description of a single specimen preserved in alcohol : — Form columnar,
thicker above, and expanding below to a large basal disk; wall of body very
rigid; capitulum smooth, with an imperfect (?), very thin cuticle; scapus beset
with very prominent knobs, many of which have a distinct, nipple-like apex ;
twelve large coronal tubercles mark the junction of the scapus with the capitulum;
most of the other knobs have a more or less distinct vertical arrangement; between
these are a few irregularly disposed ; the knobs decrease in size inferiorly, and the
lower portion of the column and the basal disk are devoid of them ; the wall of
the scapus is transversely wrinkled, and provided with a thick cuticle. The tentacles
are set in several rows, and appear longitudinally wrinkled ; the circular muscle is

Haddon — A Revision of the British Actinice.

309

short and thick; the mesoglcea (mesoderm) is very thick and solid. In the
preserved specimen the colour of the capitulum is yellowish white, slightly
streaked with brown when the cuticle persists ; that of the upper portion of the
scapus is a deep, rich brown, becoming paler below ; the uncovered portion of the
knobs is white. Dimensions : total height, 64mm. ; diameter of upper portion of
column, 33mm. ; diameter of lower portion, 24mm. ; average expanse of pedal
disc, 41 mm.

Since Fabricius, Dr. Liitken (1860) is the only author who has alluded to this
species from actual knowledge, and he says very little about it ; in fact, since the
original, imperfect description, the species has never been properly diagnosed.

A vertical, longitudinal section is given on PI. xxxv., fig. 4 ; the most noticeable
feature is the great length of the oesophagus. The rigidity of the body is due to
the well-developed mesoglcea. The circular muscle in the single specimen examined
is short and thick, and marked by several concentric lines.

Hormathia, Gosse, 1859.

Chondractininae with very contractile body wall, pillar-like when extended,
smooth or corrugated, not warty, surrounded by a single row of coronal tubercles ;
capitulum smooth, or with twelve ridges ; base expanded ; cuticle more or less
developed ; circular muscle very large ; disc slightly concave, scarcely exceeding
the column ; tentacles moderately long and slender ; perfectly retractile.

RECOGNISED SPECIES OF HOEMATHIA.

Hormathia margaritse, Gosse.
North East Scotland, Shetland.

Hormathia pectinata (R. Hertwig).

West Patagonia.

Hormathia andersoni, Haddon.
Mergui Archipelago (Burmah).

With a single exception (F. E. Schulze, 1875, p. 139), the hitherto unique species
of this genus has been unrecognized, since Gosse described it from a single
specimen. Although no specimen of the type exists, nor drawing of the contracted
animal, and though no anatomical investigations have been made upon it, I have
no doubt that the specimen on which the genus was founded belongs to this
sub-family.

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Haddon — A Revision of the British Actiniae.

Mr. Gosse was uncertain as to the exact number of the large, well-defined
warts below the margin; he says "about ten in number"; we are justified in
assuming there were twelve.

Canon Norman gave me a specimen of a Chondractinian from Shetland, which
agrees so closely with Mr. Gosse's description, that I have no hesitation in
relegating it to this genus, although Mr. Gosse describes a living and expanded
form. I have further ventured to allocate my specimen to the described species.
I was for a long time undetermined whether to do so or to make it a new
species, associated with Canon Norman's name, as I had no proof of the identity
of the two specimens in question ; but on carefully considering the question, I
could not discover any valid reason for separating them. The Shetlands, also, are
not very distant from the Moray Firth.

The Shetland specimen is very similar to an Actinian described by Dr. R.
Hertwig as Phellia pectinata, n. sp. (1882, p. 81, pi. i., fig. 7, etc.), from the channel
between Wellington Island and Patagonia, Station 307, 147 faths., and to a form
which I have recently described as H. andersoni (1888, p. 251, pi. xx.), from the
Mergui Archipelago, off Burmah.

This genus is certainly very closely allied to Dr. Liitken's genus, Chondrac-
tinia, which was introduced the following year. The absence of tubercles on the
column and its greater contractility appear to be the main distinctions. I should
hardly have considered myself justified in supporting the distinctness of the two
genera, had I not been personally acquainted with two species of each genus.
Further, the European, Burmese, and Patagonian are so closely allied, though
good species, that they naturally go together. If, therefore, the genus Chondrac-
tinia is merged with Hormathia, the species mentioned in this communication will
group themselves into two series, corresponding to those species which I have
ranged within the two genera under discussion.

Hormathia margaritse (Gosse).
(Plates xxxiii., fig. 12; xxxv., figs. 10-12.)

Hormathia margarita, g. et sp. n., Gosse, . 1859, Ann. Mag. Nat. Hist. (3), iii., p. 47.
Hormathia margaritce, Gosse, . . . 1860, Actinologia Britannica, p. 219, pi. viii. , fig. 1.
Hormathia margarita, Schulze, . . 1875, Jahresb. Com. Untersuch. Deutschen Meere, Kiel,

Exped., 1872, p. 140.
Hormathia margarita, Andres, . . . 1884, Le Attinie, p. 364.

Previously -knoivn Localities. — Moray Firth, near Banff ; deep water, clasping
a living Fusus antiquus (P. H. G.) ; N.E. Scotland, 69 faths. Station No. 79,
on Fusus antiquus (F. E. S.).

Haddon — A Revision of the British Actinia?.

311

Description of a single preserved specimen. — Body very contractile ; base
broader than column, somewhat recurved ; column transversely rugose, apparently
due to contraction ; upper portion of contracted body with twelve small elongated
"coronal" tubercles or ridges, which extend some distance along the invected
capitulum ; circular muscle very strong.

Colour. — Yellowish in spirit.

Dimensions. — Average diameter at base 13 mm. ; height of fully contracted
specimen 6 mm.

Locality. — Shetland, Rev. A. W. Norman.

I have previously stated that I have had doubts whether I should provisionally
keep this specimen distinct from the above species. This was simply on account
of the absence of any information, first as to the appearance of a contracted
H. margaritce, and secondly, as I had no information as to the appearance of the
animal when alive. Canon Norman doubtfully labelled it " Tealia digitata" and
on sending it to me drew my attention to its probably being distinct therefrom.
I mention this as it is direct evidence that it probably resembled that species when
alive. A comparison of Mr. Gosse's figure of this species (1860, pi. viii., fig. 6) and
the accompanying figures of C. digitata (Pi. xxxn, figs. 9 & 10) will indicate the
general resemblance between them, which would doubtless be still further increased
were contracted specimens compared.

The mesoglcea of the specimen investigated is not so thick as in that of
Chondr actinia digitata. A comparison of figs. 12 & 6, PI. xxxv., will show distinctions
between these two species. The mesoglosal circular muscle is very strong, and
exhibits certain well-marked characters ( PL xxxv., figs. 10, 11). In a vertical section
the muscular masses are arranged in regular tiers, so that the dissepiments between
them appear as parallel lines which externally, *. e. towards the ectoderm, are
looped something like the tracery of a Gothic church window. It is probable that
this peculiar disposition of the muscles will prove of great service in the future
identification of this species. The specimen was a female.

Chitonactis, Fischer, 1874.

Chondractininse, with thick mesogloea, permeated by strands of "mesodermal"
muscle-fibres ; circular muscle very large ; capitulum smooth ; twelve pointed
coronal tubercles ; scapus provided, especially in its upper portion, with pointed
papillae more or less regularly disposed, twelve rows being prominent. Cuticle
largely developed on the papillae.

From a personal knowledge of some examples of Gosse's Bunodes coronata, which
he obtained from the Bay of Biscay, M. Fischer found that the English author had
allocated the species to the wrong genus, and therefore he proposed a new genus
for it (1874, p. 226).

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Haddon — A Revision of the British Actinice.

SPECIES OP THE GENUS CHITONACTIS.

Chitonactis coronata (Gosse).
English Channel ; Bay of Biscay ; South-west of Ireland.

Chitonactis marioni (Haddon).
Off South-west of Ireland, 325 faths. ; Bay of Biscay.

Chitonactis spinosa (R. Hertwig).

South Indian Ocean, lat. 53° 55' S.; long. 108° 35' E.; 1950 faths. ; off Japan,
1875 faths.

Chitonactis minuta (R. Hertwig).
South Indian Ocean, lat. 46° 16' S. ; long. 48° 27' E. ; 1600 faths.

(?) Chitonactis longicornis (Verrill).
Off North-east coast of America, 100-325 faths.

Chitonactis coronata (Gosse).

Bunodes coronata, n. sp., Gosse, . 1858, Ann. Nat. Hist. (3), ii., p. 194.
Bunodes coronata, Gosse, . . . 1860, Actin. Brit., p. 202, pi. vii., fig. 4.

Bunodes coronata, Schulze, . . 1875, Jahresb. Coin. Untersuch. Deutschen Meere, Kiel, Expd.,

1872, p. 140.

Chitonactis coronata, Fischer, . . 1874, Nouv. Arch. Mus. d'Hist. Nat. x., p. 226.
Chitonactis coronata, Andres, . . 1884, Le Attinie, p. 124.

Distribution — S. Devon, moderately deep water, 20 faths. (P. H. G.) ; N. E. of
Hasborough Station, 108, 12 faths. (F. E. S) ; Port of Arcachon, 20-45 faths.
(P. F.); South-west of Ireland, 50 faths. (A. C. H.).

Just before sending to press the present Memoir I was entrusted with some
Actiniae, dredged off the south-west coast of Ireland in June, 1888 ; the Report of
the Expedition which dredged these specimens will shortly be published in the
Proceedings of the Royal Irish Academy. Having no time at my command,
I am reluctantly obliged to postpone an anatomical investigation on these forms.
Amongst them were two specimens which, from their general appearance, and
their agreement with the accounts given us by Mr. Gosse and M. Fischer, I am
confident belong to the above species.

Haddon — A Revision of the British Actinice.

313

The following is a description of the two preserved and retracted specimens
sent to me : —

Base much expanded, clasping the shell of a Fusus inhabited by a hermit-crab ;
column transversely wrinkled, studded with small conical pointed warts which do
not appear to have any definite arrangement, but are more numerous at the upper
portion of the contracted body, and are absent, or nearly so, on the expanded base ;
the coronal tubercles not distinguished from the others by size ; the invection of
the upper portion of the body is so complete that no distinct orifice is present when
fully contracted. The body wall is thin but not flaccid ; the mesogloeal circular
muscle is well developed. The specimens had in spirits a dirty drab colour. The
oesophagus and disc had traces of a scarlet colouration. Average diameter of base
about 25 mm. ; average height of contracted specimens, 15 mm.

Chitonactis marioni, n. sp.

(Plates xxxi., figs. 1, 2 ; xxxiii., figs. 7, 8, 9 ; xxxv., figs. 8, 9.)

Form. — Body columnar when extended ; conical when contracted, with ex-
panded base attached to a spine of Dorocidaris papillata. The basal disk extends
along the spine to about twice the average diameter of the column ; the edges of
the basal disk fuse on the opposite side of the spine. The column is provided with
irregularly-disposed, small, unequal, sharply-pointed tubercles ; these are farther
apart and smaller towards the base. The general surface of the column is quite
smooth. The upper portion of the column, or rather of the scapus, where it passes
into the capitulum, is vandyked, each of the triangular spaces whose apex points
upwards being provided with a strong tubercle. The capitulum is short, smooth,
with twelve ridges corresponding with the apices of the tuberculated triangles just
mentioned ; when contracted, these ridges and the tubercles give the appearance of
an irregular twelve-rayed rosette. Tentacles rather short and thin ; probably 48
in number (6 + 6 + 12 + 24). Disc slightly conical ; mouth an elongated slit at
right angles to the long axis of attachment.

Colour. — Body pale greenish-grey ; tubercles of a darker colour ; capitulum
pink, the vandyked lower margin and the ridges being white ; the latter thus
dividing the capitulum into twelve pink panels. Tentacles, primary and secondary,
pale-pink, irregularly splashed with madder brown ; on their oral aspect a few are
simply translucent pink ; the remainder are longitudinally striped by extremely
delicate lines, usually with the proximal portion of the tentacle strongly-coloured

TRANS. ROY. DUB. SOC, N.S. VOL. IT., PART V.

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Haddon — A Revision of the British Actinice.

madder brown ; tertiary tentacles translucent white. There are white lines
between the bases of the tentacles, evidently indicating the mesenteries, disc
pinkish, irregularly but finely splashed with madder brown, lips white, oesophagus
pale flesh-colour. In the contracted spirit specimen the ground colour of the
column has bleached, and the tubercles have a more yellowish tinge.

Dimensions. — Height, when extended, about 30 mm.; diameter of column
16 mm.; extreme length of pedal disc 35 mm.; length of tentacles 10 mm. The
measurements of the specimen in spirit are : height 13*5 mm. ; narrow diameter of
middle of column (i. e. at right angles to line of attachment) 18 mm. ; length of
pedal disk 34 mm.

Locality. — Attached to a spine of Dorocidaris papillata, from 325 fathoms off the
south-west coast of. Ireland, 53 miles W. \ S. of Dursey Head, fine sand. (A
reference to the capture of this specimen will be found in the "Narrative of the
Cruise" in the '-'Second Report on the Marine Fauna of the South-west of
Ireland," Proceedings, Royal Irish Academy, vol. i., 3rd ser., p. 35, 1888.)

On my submitting a sketch of this specimen to Professor Marion, he informed
me that it was similar to others which had occurred in the " Travailleur "
dredgings ; at the same time he kindly gave me proof cojnes of three unpublished
plates which were intended to illustrate the final Paper, of which a preliminary
account has appeared (1882). On one of the plates was figured a form which,
according to a pencil memorandum, Professor Marion regarded as a young
example of his Chitonactis richardi. Fortunately I possess a fair series of young
specimens of this species which, as a matter of fact, very closely resemble the adult
form. Apart from this, there are a sufficient number of characters which
serve to distinguish the two species in question. It affords me great pleasure,
therefore, to associate this species with the name of my distinguished French
colleague.

In a vertical section it is seen that the circular mesoglceal muscle has a
considerable longitudinal extension : the disposition of the muscular strands is
shown in PL xxxv., fig. 8. The mesoglcea of the body- wall is not thick ; that of the
mesenteries is thin ; it recalls that of Paraphellia. The general character of the
retractor muscle of the mesenteries (PI. xxxv., fig. 9) is somewhat similar to that in
Actinauge. It is instructive to compare my figure 8 with those given by Professor
Hertwig for Cereus spinosus (1882) in I. c. pi. vi. fig. 1, and pi. viii. fig. 6.

Haddon — A Revision of the British Actiniae.

315

? Chitonactis longicornis.

Urtieina longicornis, n. sp., Verrill, . 1882, Am. Journ. Sci., xxiii., p. 222.
Actinauge longicornis, Verrill, . . 1883, Bull. Mus. Comp. Zool., xi., p. 53, pi. v., figs, 1, 2.
Actinauge longicornis, . . . 1885, Rep. U. S. Fish. Com. for 1883, pp. 514, 534, pi. viii.,

fig. 21.

This form appears to me to belong to the genus Chitonactis.

Prof. R. Hertwig, in his "Report on the Actiniaria," collected by the "Chal-
lenger," (1882), rediagnoses the genus Cereus of Oken, and modifies that genus as
emended by Prof. Verrill (1869, p. 480). By so doing he necessarily eliminates the
type species (C. bellis = C . peduncutatus) from the genus. I agree entirely with
Prof. Verrill's interpretation of the genus Cereus, and consequently cannot agree
with Dr. Hertwig in his " wish to attach more importance in the diagnosis to the
papillose nature of the wall, in order to establish a sharp distinction between this
genus and Sagartia," (1882, p. 76). This is almost accepting the genus as defined
and obscured by Prof. Milne Edwards (1857, pp. 263-273).

As I cannot admit that the new species described by Dr. Hertwig as Cereus
spinosus (1882, p. 76, pi. i., figs. 3—5, etc) belongs to that genus, another resting-place
must be found for it. Prof. Marion informs me by letter, and I perfectly agree
with him, that he considers that this species belongs to the genus Chitonactis.
I propose therefore to name it Chitonactis spinosus (Hertw.), and it has the
appearance of being a very typical member of that genus.

Equally characteristic of the genus Chitonactis is the species which Prof.
Hertwig has named Bunodes minuta, n. sp. (1882, p. 84, pi. ii., fig. 12 a & b). I have
already alluded to this species, and need only say that the description of it, as
given by my German colleague, entirely corresponds with the position to which I
would assign it. The genus Bunodes, as represented by its type species, B. verru-
cosa (Pennant) = B. gemmacea (Ellis) certainly requires to be anatomically studied ;
but I venture to prognosticate that it will not prove to be a member of the
Sagartidae.

Actinauge, Verrill, 1883.

Chondractininae with very thick mesoglcea ; circular muscle very large ;
capitulum with twelve ridges corresponding with the twelve coronal tubercles ;
scapus strongly tuberculate, or nodulate ; cuticle present, especially on the
tubercles ; inner three rows of tentacles with a swollen base.

2 Z 2

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Haddon — A Revision of the British Actinice.

This genus was erected by Professor Verrill for some large forms which he
took to be the Actinia nodosa of Fabricius. From a personal examination I am
satisfied that the latter is quite distinct from Prof. Verrill's Actinian, which in its
turn is very closely allied to the Chitonactis richardi of Prof. Marion (1882, p. 460).
The bulbous base of the inner tentacles and the character of the tubercles and
of the capitulum are sufficient to remove these forms from the genus Chitonactis,
so we may utilize Prof. Verrill's genus while discarding his species.

Prof. Verrill describes the genus in the following terms : —

"Large Actinians, with the tentacles and upper part of the body capable of
involution. Integument of body of two kinds : that of the lower part is firm, thick,
and more or less coriaceous or parchment-like, with persistent, solid warts or
tubercles, usually in vertical rows, and sometimes partially covered with a thin
chitinous epidermal coating ; that of the upper part of the body forms a marginal
brighter-coloured band, below the tentacles, where it is soft and lubricous, secreting
mucus abundantly, and rising into longitudinal ridges, crests, or oblong tubercles,
which run to and unite with the basis of all [some of] the tentacles. The basal disk
may be broad and flat, adherent, or it may be bulbous, clasping mud, or it may
ensheathe the branches of Gorgonise, etc. Tentacles long and large, contractile
[those of the inner cycles having a basal bulb] ; lips with large folds and gonidial
grooves." (1883, p. 50).

I have quoted Prof. Verrill's diagnosis of the genus in full, but I would modify
it by stating that the capitular ridges run to some, not to " all " the tentacles, and by
adding a note on the bulbous base of the tentacles, these alterations are placed in
brackets in the foregoing description. Lastly, I would speak of them as " Large
Chondractininse, with the tentacles," etc.

Prof. Verrill believed that this genus " is also closely allied to Urticina, Ehr.
(Tealia, Gosse), of which the type is U. crassicomis \TJ. felina~\. But the latter has
the integument soft and lubricous over the whole body, and there is no marked
specialization of the submarginal zone : the tubercles, when present, are small, not
much thickened, and of the nature of true suckers for attaching foreign substances;
and when not in use may so contract as to disappear entirely ; the submarginal
zone is nearly smooth, with a definite upper margin, and there are no vertical
ridges running in on the disk to join the bases of the tentacles, as in this genus
and in Actinerus." — [Verrill.] It is now certain Urticina felina is very different in
every respect from any of the known species of Actinauge.

Haddon — A Revision of the British Actinice, 317

SPECIES OF THE GENUS ACTINAUGE.

Actinauge sp. (?) (A. nodosa, Verrill, not of Fabricius).
North-east coasts of America, 86-1098 faths.

Actinauge richardi (Marion).
Bay of Biscay (considerable depths) ; south-west of Ireland, 50—110 faths.

Actinauge (sp.) ?

Urticina nodosa, Verrill (not of Fabricius), 1873, Amer. Journ. of Sci., vi., p. 440.

Urticina nodosa, Verrill, .... 1874, ibid., vii., pp. 413, 500, pi. vii., fig. 7.

Urticina nodosa, Smith and Harger, . . 1874, Trans. Connect. Acad., iii., pp. 11, 54.

Urticina nodosa, Verrill, .... 1882, Amer. Jour. Sci., xxiii., pp. 224/315.

Actinauge nodosa, Verrill, .... 1883, Bull. Mus. Comp. Zool., xi., p. 50, pi. vi., figs.

6-Sa.

Actinauge nodosa, Verrill, .... 1885, Eep. U. S. Fish Com. for 1883, pp. 415, 534, pi. v.,

fig. 20.

Abundant off the north-east coasts of America, from 86—1098 faths.

This species has been well described by my American colleague so far as its
external appearance is concerned (1883). From the description given by Dr.
Fabricius of his Actinia nodosa, there was nothing to lead Prof. Verrill to suppose
that his was other than that species, or at most a variety of it. Thanks, however,
to a personal acquaintance with a single specimen of the Greenland species, which
was named by Dr. Liitken, I am able to state definitely what it really is (p. 308),
and I find that the typical American species is quite distinct. It is, however, quite
possible that the very nodular form described by Prof. Verrill as A. nodosa, var.
tuberculosa, is the true " Actinia 1} nodosa. The description (1883, p. 53, pi. vi., fig 7,
and 1885, pi. v., fig. 2'0a) agrees perfectly well with the specimen I have examined,
with the exception that in Prof. Verrill's form, " The upper retractile border
[capitulum] has irregular, strong, longitudinal, unequal crests." In the
specimen I examined the capitulum is smooth, or at most with fine longitudinal
creases, due to contraction. But Prof. Verrill himself says, " This is a remarkable
form, perhaps a distinct species."

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Haddon — A Revision of the British Actinice.

If my observations are correct, the type species of the genus Actinauge is
without a name ; for it would be very misleading to retain the specific name
of nodosa, owing to its history, even though A. nodosa, Fabr., is relegated to
another genus. We might retain one of the two varietal names of coronata, Verr.,
or tuberculosa, Verr., as the specific name of the type. For the following reasons I
cannot see my way to so doing. Prof. Verrill overlooked the presence of the
tentacular bulbs in the type forms, and we have no information whether they are
present in these two varieties. If present, it would form strong evidence in favour
of their being varieties of the type species of Actinauge : if absent, they probably
belong to different genera. The latter, as I have just mentioned, may possibly be
the true Actinia ( Chondr actinia) nodosa. The former certainly suggests the genus
Hormathia (see p. 309), or perhaps a variety of Chondractinia (see p. 305). Prof.
Verrill, however, informs us that " Intermediate states between this and the
normal form [ Actinauge] are not rare, (1883, p. 53). As so much doubt exists,
I prefer to leave the specific name of this form still an open question; but if
distinct, it might be named after the distinguished American zoologist who has
so greatly advanced our knowledge of American Marine Zoology.

The American specimens are " usually " white, dull pale-red, flesh-colour, or
salmon ; . . . sub-marginal zone is bright-red, orange-brown, or chocolate-
brown, often in lighter or darker stripes. The tentacles are usually dark-pink,
salmon, or orange-brown, varying to dull-red, or chocolate-brown. Disc usually
orange, or reddish-brown, or chocolate, with lighter and darker radii, [l. c. 1883,
p. 52).

This species occurs abundantly off the North-east coasts of America, from 86—
1098 faths., Verrill (1885, p. 534). Prof. Verrill (1883, p. 52) says, " I have also re-
ceived two examples from Denmark, through Dr. Chr. Liitken, of the Copenhagen
Museum, which, so far as can be seen from the alcoholic specimens, agree perfectly
with some of our less nodose varieties. These were sent as Actinia digitata, Miiller.
But the Actinia (or Tealia) digitata of Gosse and several other European writers
may be a distinct species."

Owing to the kindness of Canon Norman, I have been able to examine two
spirit specimens of the above species. They undoubtedly appear to be quite dis-
tinct, specifically, from the British specimens of A. richardi, which I have studied;
but then, again, there are strong resemblances between the former and the figures
on Prof. Marion's unpublished plate. We can only await the decision of Profs.
Verrill and Marion as to the identity of their forms.

Haddon — A Revision of the British Actiniae.

319

Actinauge richardi (Marion).
Plates xxxi., fig. 6; xxxm., fig. 10; xxxiv., figs. 5-7.)

Chitonactis richardi, n. sp., Marion, . 1882, Comptes rendus, xciv., p. 460 (trans. Ann. Mag. Nat.

Hist. (5), ix., 1882, p. 335).
Chitonactis richardi, Andres, . . 1884, Le Attinie, p. 130.

(?) Actinia tuberculata, n. sp., Cocks, . 1851, Nineteenth Annual Rep. Roy. Cornwall Polytech. Soc,

p. 7., pi. ii., fig. 3.
(?) Tealia (?) tuberculata, Cocks, Gosse, 1860, Actin. Brit., p. 217.

This handsome species was referred to, but not fully described, by Professor
Marion (1882). On submitting a coloured sketch of some Irish specimens of Actiniae
to Prof. Marion, he assured me that this was his species, and at the same time he
kindly sent me proofs of some unpublished plates of his which entirely confirmed
his statement. I would take this opportunity of acknowledging the cordial
manner in which this distinguished French zoologist has rendered me assistance
by correspondence, and his kindness in sending to me the proofs of his unpublished
plates.

Prof. Marion also informed me, by letter, that he had obtained "this species from
70 metres to 2000 metres. It is very polymorphic : the tubercles of the column
may increase or almost disappear. The same obtains for the cuticular layer.
The foot is prehensile, forming an ampulla, or it may seize hold of an-Holtenia
or an Isis, and develop lobes. The tubercles of the arm even may be somewhat
diminished."

DESCRIPTION OF SOME IRISH SPECIMENS.

Form. — Body cylindrical, both when extended and contracted, and preserved
in alcohol ; general surface of column smooth, studded with rounded warts, which
have a tendency to run into longitudinal rows ; pedal disc not expanded, even
when the animal is attached to a flat surface ; usually the pedal disc is bent round
ventrally, the edge being constricted so as to form a cup-shaped concavity, which
is filled with sand. The pedal disc thus grips the bottom, and forms an
efficient sand-anchor. In two cases the base surrounded a small Natica shell.
The capitulum is smooth and slimy, and traversed by twelve strong ridges, each
of which divaricates above, and is continuous with the base of a tentacle of the

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fourth cycle. Tentacles in five cycles, 96 in number (6 + 6 + 12 + 24 + 48).
The inner rows are of moderate length, and provided with a well-marked swelling
on the abactinal (ventral) aspect of their base. This enlargement is especially
prominent on the tentacles of the three inner cycles. The tentacles of the
outermost row are short, without basal bulbs; oral disc smooth, flat; mouth
usually oval, with tumid lips.

In the contracted specimens the column is distinctly nodular, the nodules
being very irregular both as to size and distribution. A general vertical
(longitudinal) arrangement can, however, be occasionally discerned. The
tubercles are larger in the upper portion of the column, twelve very prominent
ones usually occurring at the bases of the capitular ridges. The nodules become
much smaller at the proximal end of the column, so that the constricted edge of
the basal disc may be described as tesselated.

Colour. — Column dirty- white, tinged with green; tubercles dull-green;
capitulum whitish ; tentacles white, or flesh-colour, the oral aspect of the two
inner rows variously streaked with madder, or chocolate-brown, sometimes almost
of a burnt sienna-brown ; basal bulbs always white ; outermost tentacles not
marked with brown ; disc white, streaked and splashed with the same shades of
brown as the tentacles ; lips usually white ; oesophagus either deep madder brown
or mahogany colour, or whitish, streaked with brown. In one specimen the disc
and all the tentacles were of a pure translucent white, the deep reddish-brown
colour of the oesophagus showing up in strong contrast through the gaping mouth.

Dimensions. — The following are the measurements of four specimens pre-
served in alcohol: — 23 mm. high x 19 mm. in diameter; 37 x 29 ; 43 x 28 ;
45 x 30. ■

Locality. — 50—110 faths. off the south-west coast of Ireland. (^1) one specimen
from 70-80 faths, 5-8 miles W. of Great Skellig ; fine muddy sand, anchored in the
sand ; (B) one specimen, attached to shell of a dead Pinna, 100 faths., 35 miles
W. f S. of Dursey Head, sand ; (C) six specimens, two surrounding shell of a small
dead Natica, the remainder with basal concavity grasping the sand ; 100 faths., 43|
miles W. f S. of Dursey Head ; (B) one specimen from 50 faths., off Glandore.

The great development of the mesoglcea is a noticeable feature in Actinauge
richardi. The retractor muscles of the mesenteries extend throughout nearly their
whole width (PI. xxxiv., figs. 6 & 7). Even those of the quaternary mesenteries are
developed (fig. 7, iv.). The circular muscle of the endoderm (figs. 7 & 9, c. m. en.)
is not conspicuous. The ectoderm is rubbed off in places, but usually on the
tubercles it persists, being protected by a thick cuticle (fig. 8, cu.). The circular
sphincter muscle is well developed: its character in longitudinal section is seen in
tig. 9. The bulbous base of the three inner rows of tentacles is due to a local
thickening of the mesoglcea.

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321

I have, doubtfully, referred A ctinia tnberculata (Cocks) to this species. The account
in Mr. Gosse's monograph, which extends the original description, certainly sup-
ports the conclusion that it may be a variety of Actinauge richardi. Through the
kindness of Mr. Gosse I have been enabled to examine a life-size drawing made
for him by Mr. Cocks ; in this drawing the tubercles are represented as relatively
much smaller and more numerous than in the published figure ; the latter certainly
more closely resembles the appearance of the Irish specimens. Some of the
tentacles are said to be " bifurcated." From the drawing just referred to, I am
inclined to believe that the bifurcation is a slight misinterpretation of the bulbous
base of the tentacles. In our specimens the swelling was, in some cases, so promi-
nent as quite to suggest a bifid tentacle. In addition to this, some of the tentacles
in Mr. Cocks' unpublished sketch are very irregular ; whether this is due to an
abnormal growth of the tentacles, or whether Mr. Cocks has inadvertently drawn
torn tentacles, I cannot say ; but it may be confidently asserted that these tentacles
are not normal.

Paraphellia, gen. nov.

Chondractininae with thin mesoglcea; circular muscle relatively small; capi-
tulum smooth, no coronal tubercles ; scapus smooth or slightly corrugated; cuticle
not developed ; body encrusted with sand ; base large, often very widely
extended.

This is a new genus, erected for a single species, which has hitherto only
occurred off the south-west of Ireland.

Paraphellia expansa (Haddon).
Mouth of Bantry Bay, South-west of Ireland ; 40 faths.

Paraphellia expansa (Haddon).

(Plates xxxii., figs. 1-4 ; xxxiil, fig. 6; xxxiv., figs. 1-4.)

Chitonactis (?) expansa, n. sp., Haddon, . . 1886, Proc. Eoy. Irish Acad. (2), iv., Science, p. 616.

Form. — Column, scapus usually very depressed and turban-shaped, but when
weakly or dead obtusely conical, corrugated. Base flattened out and much and
variably extended in different directions, the edges crenulated by the insertion of
the mesenteries, of which there are about 100 ; when dead the base may be
withdrawn beneath the extended scapus ; capitulum short, invisible when the

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animal is fully open, crenulated by the mesenteries of the three inner cycles of
tentacles when the animal is partially closed, and when the animal is retracted it
almost completely covers over the tentacles.

Tentacles short, conical, quadricyclic, 48 in number (6 + 6 4- 12 4- 24).

Disc perfectly flat.

Mouth, with fairly prominent lips, oval or round when open ; usually more or
less cruciform when closed.

Colour. — Column, base, translucent butt'; scapus, pinkish or flesh-coloured;
capitulum, translucent pink ; the mesenteries of the primary cycle of tentacles are
marked by a pair of somewhat triangular deep madder-coloured spots, the three
intervening lobes having a pale yellow spot in their centre.

Tentacles pale translucent madder, with a pale brown terminal spot, and
lateral rows of similar spots.

Disc, dark sepia, with six pairs of radial cream-coloured lines extending from
the bases of primary tentacles to the mouth, and six pairs of similar smaller
converging lines, which arising from the bases of the secondary tentacles die away
before reaching the mouth. A row of small cream-coloured spots runs down the
central line of each of these twelve areas. A pair of short brown lines extends
from the base of each of the tertiary tentacles ; this is surmounted and prolonged
by a row of small cream-coloured spots, which half-way across the disc unite to
form a single median row, which terminates near the mouth : in the triangle thus
formed by these converging rows of spots is a short central row of similar spots.

Mouth, lips of a fleshy-brown colour ; inside of mouth of a deep madder-brown
colour.

When obtained the body of one specimen was entirely covered with grains of
sand and broken shells (PI. xxxn., figs. 1-4) ; the other with fine sand only
(PI. xxxiii., fig. 6).

Dimensions. — Diameter of base, 21-25 mm. ; diameter of scapus, 12 mm. ;
diameter of disc, 7 mm.

Habitat. — Mouth of Bantry Bay ; depth, 40 faths. ; bottom coarse sand.

Two specimens of this new genus and species were obtained from the same
locality. The first was found in 1885, and described the following year (Haddon,
1886, p. 616); in the latter year the second specimen was dredged; this specimen
closely resembled the preceding. I believe they are sufficiently distinct from
previously described species to warrant the erection of a new genus to contain
them.

The mesoglcea is relatively feebly developed in this genus, as is specially
noticeable in the oesophagus and mesenteries (PI. xxxiv., figs. 1, 2 & 4). That of
the body wall is of medium thickness. The longitudinal retractor muscles of the

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323

primary mesenteries are narrow and reniform in section below (fig. 2), but are
broader above (fig. 1). •

The secondary and tertiary mesenteries alone bear generative organs. The
single specimen sectionized was a female ; the secondary mesenteries had their
ovaries in their lower third (figs. 2 & 3), while those of the tertiary mesenteries
occurred on the middle third. The mesenteries of the fourth rank nowhere projected
above the endoderm in this specimen.

The circular muscle of the endoderm of the body-wall (fig. 4) is well developed,
and, as in other Chondractininse, separates the mesoglcea of the mesenteries from
that of the body- wall.

As stated above (p. 304), I do not think the time has yet arrived when it is
possible to satisfactorily classify the majority of Sagartians. I wish, however, to
take this opportunity of making a few notes on some British examples of those
which do not belong to the sub-family Chondractininse.

The genus Sagartia, Gosse, sensu stricto, must be retained for S. miniata, Gosse
(? S. elegans, Dal.), S. venusta, Gosse; S. nivea, Gosse; and S. rosea, Gosse, as
has already been pointed out (p. 302). Doubtless many non-British forms will
find a place here ; but it must be by their conforming in structure to these type
species. The definition of the genus cannot be modified in any important manner.

The form called by Mr. Gosse Sagartia (Scyphia) bellis (Ell. and Sol.) is the
type of the genus Cereus (Oken). Its more correct name is Cereus pedunculatus
(Penn.).

If strict priority be observed, the species commonly known as Actinoloba
dianthus (Ell.) will have to be called Metridium senilis (Linn.).

The genus Cribrina was introduced by Prof. Ehrenberg (1834, p. 264) for those
Actiniae, il poris lateralibus instructa," with the following as its species : —
1. C. verrucosa, E. (= A. verrucosa, Lam. = Hydra verrucosa, Gaertn.) ; 2. C. glandu-
losa, E. (= A. glandulosa, Otto); 3. C. coriacea, E. (= A. coriacea, Cuv. = A. senilis
Linn.); 4. C. effoeta, E. (= A. effoeta, Bast.; nec Priapus polypus, Forsk.); 5. C.
polypus, H. and E. (= P. polypus, Forsk. = A. priapus, Gmel. = A polypus, Blainv.,
nec. A. effoeta, Rapp.). As a general rule, the first-mentioned species of a new
genus is to be taken as its type ; but in this case the type is undoubtedly the
fifth species, C. polypus. It is evident that it was intended to publish the genus
with this species as its type in the "Symbolae physical, " which was brought out by
Herren Ehrenberg and Hemprich ; but I can find no trace of this having been
done. At all events, Prof. Ehrenberg associates Hemprich's name with his own
both for the genus and for this species, but for no other species. Thus the author
regarded it as typical. The genus is based upon, and named from, the presence of
lateral pores ; none of the first three named species are perforated ; therefore on
this ground alone we are justified in limiting the generic name to its perforated

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members. . The genus Cribrina then has G. polypus (Forsk.) for its type species. I
am aware that this species is possibly a synonym for C. ejfoeta (Linn.).

The genus Calliactis, Verrill (1869, p. 481), is very closely allied to Cribrina,
s. s. If they are identical the older name must stand.

It is now admitted by many zoologists that A. parasitica, Couch, is A. effoeta,
Linn. ; but Dr. Andres in his monograph (1884) makes A. effoeta, Linn., and
A. viduata, MiLll., the same species; and he gives A. parasitica as a synonym of
A. rondeletii, D. Ch. Personally, I am inclined to follow M. Fischer (1874) and
others in regarding A. parasitica as a synonym of A. effoeta, Linn, (not, however,
"i. effoeta" as. M. Fischer spells it). The correct name of this form is therefore
Cribrina effoeta (Linn.).

The only anatomical account we have of the genus Phellia consists of two semi-
diagrammatic figures of Phellia limicola, Andr. (figs. 2 & 3), in the Introduction of
Prof. Andres' monograph (1884, pp. 73, 74). From these figures it appears that
only the six primary pairs of mesenteries are perfect, and at the same time they
alone bear the generative organs. Acontia are present. No mesoglceal circular
muscle is indicated as being present.

While Phellia may be placed among the Sagartians — by the possession of
acontia — we cannot regard it as belonging to the Chondractininse.

Sagartia, sp.

Figures of a Sagartian are given on Pis. xxxn., fig. 6. ; xxxiii., fig. 5, which I
have not time to properly describe or identify, and I prefer to leave them un-
named to hazarding an untrustworthy determination. It was found attached to
a Caryophyllia at a depth of 16 faths., 42 miles off the Great Skellig, south-west
of Ireland, in 1886.

Base expanded, attached to side of a large Caryophyllia (Haddon, 1888, p. 36) ;
scapus translucent pink, with attached grains of sand; capitulum elongated,
translucent white ; opaque white spots at base of tentacles ; tentacles short,
swollen, conical, pinkish, with madder ring near their base ; disc pinkish ; lips
madder.

Haddon — A Revision of the British Actinias .

325

Gephyra dohrnii, Von Koch.
(Plates xxxi., figs. 3-5 ; xxxm., figs. 3, 4.)

Gephyra dohrnii, g. and sp. nn., Von Koch,
Gephyra dohrnii, Andres,
Gephyra dohrnii, Marion,

Gephyra dohrnii, Hertwig,
Sayartia dohrnii, Andres, ....
Sayartia dohrnii, Carus, . .
Gephyra dohrnii, Haddon,

1878, Morpb. Jahrb. rv., Suppl., p. 78, pi. v.

1880, Mitth. Zool. Stat. Neapel., ii., p. 314.

1882, Comptes rendus, xciv., p. 458 (transl. in Ann. Mag.

Nat. Hist. (5), ix., 1882, p. 334).
1882, " Challenger " Eep. Actiniaria, vol. vr., pt. xv., p. 86.
1884, Le Attinie, p. 166.
1884, Prod. Faun* Medit., i., p. 70.
1886, Proc. Eoy. Irish Acad. (2), iv., Sci., p. 616.

Distribution. — Mediterranean, Bay of Biscay, South and South-west of Ireland.

DESCEIPTION OF IRISH SPECIMENS.

A. Column smooth ; base large and thick, more or less surrounding the stems
of a Tubularian, to which it is attached, sometimes completely enwrapping them, the
two edges of the basal disc fusing to form a short open tube ; no horny or cuticular
deposit was noticed. The disc and tentacles can be completely retracted ; in that
condition the column is conical in form.

Tentacles short, conical, but rather slender, tricyclic, 12 + 12 + 24 ; the ten-
tacles of the first two cycles are about of equal length ; those of the outer row
are shorter than the others.

Disc raised, produced in the centre into a turban or even trumpet-shaped oral
protuberance ; mouth more or less circular.

Colour. — Column pale, pinkish orange, often more pink, especially the ventral
surface of the disc ; tentacles, primaries slightly darker than the disc ; tertiaries
lighter, translucent, without any markings.

Disc translucent pale orange, with 24 pale radiating lines, indicating the
mesenteries ; oral portion of disc with 12 dark orange lines, which are inclined to
be thicker towards the periphery. This portion of the disc is separated from the
remainder by a white circle ; throat deep orange. The twelve primary tentacles
have an almost complete deep orange ring at their base.

Locality. — About 30 miles off the Fastnet, south-west of Ireland, 80 faths. ; and
9 miles south of Glandore, 40 faths.

B. These specimens were taken on another occasion, and the following notes
were taken : — Body translucent orange or flesh colour ; disc translucent, white

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ring round mouth ; the insertions of the mesenteries appear as double white
radial lines ; oesophagus pinkish orange or flesh colour ; tentacles translucent
flesh colour, with darker line round the base and at the tip ; mouth at right angles
to long axis of attachment. Tentacles, apparently, 12 + 12 + 24.

Locality. — 5—8 miles west of Great Skellig; south-west of Ireland, 70-80 faths.

C. At the same time the following Actiniae were obtained, which I take to be a
variety of the same species (pis. xxxr., fig. 3; xxxiii., figs. 3 & 4). Colour, uniform
bright cherry ; disc and base expanded ; scapus constricted ; mouth nearly cir-
cular ; diameter of disc 14 mm. The base secretes a cuticular secretion. Formula
of tentacles, 12 + 12 + 24 + 48 = 96.

Same locality as preceding ; attached to stems of Tubularia, &c.

On submitting coloured sketches of these specimens to Prof. Marion, he
informed me that " your Gephyra dohrnii is identical with the Mediterranean
forms." Its range is now extended from the Mediterranean to British waters. So
far as they have gone, my investigation on the anatomy of this form, on specimens
both from the south-west of Ireland and the Bay of Naples, proves that it belongs
to the series of typical Sagartians ; but I cannot regard it as belonging to the
genus Sagartia, as above restricted.

I venture to call Prof. Verrill's attention to the need of re-examining his
Sagartia spongieola (1883, p. 47, pi. vi., fig. 3 ; and 1885, p. 534, pi. vii., fig. 200).
It has very close resemblance to this species.

Fam. EDWARDSIDiE, Andres (1880).

Elongated Actinia? with a vesicular base ; eight mesenteries only present,
including two pairs of directive mesenteries ; the remaining four mesenteries are
unpaired ; all the mesenteries bear reproductive organs ; tentacles simple, usually
more numerous than the chambers of the ccelenteron.

Sole genus. — Edwardsia, Quatrefages (1842).

Column long, cylindrical, divided into capitulum, scapus, and physa ; the
capitulum and physa are retractile, the scapus usually invested with a friable
cuticle ; tentacles variable in number, from 16—32 in the adult condition
(occasionally 8 in number ?)

The number and disposition of the mesenteries are alone sufficient to render

Haddon — A Revision of the British Actinias.

327

the genus Edwardsia well denned, and, in the present state of our knowledge,
sufficiently so to warrant it standing as the sole genus in the family of the
Edwardsidas.

Prof. Andres (1883) subdivides the Edwardsidae into two genera — Edwardsia,
provided with 16 tentacles; and Edwardsiella, with more than 16 tentacles. Other
characters are mentioned, none of which, however, appear to be of much value. As
the number and arrangement of the tentacles in the Edwardsidse are so irregular,
I prefer, with my friend Mr. G. Y. Dixon (1886), to relegate all the species to the
one genus.

BRITISH SPECIES OP EDWAEDSIA.

Edwardsia beautempsii, Quatrefages. Edwardsia allmani, M'Intosh.
,, carnea, Gosse. ,, goodsiri, M'Intosh.

,, timida, Quatrefages. ,, tecta, n. sp.

(?) E. Claparedii, Pancer sp.

Edwardsia beautempsii, Quatrefages.
(Plates xxxm., fig. 17 ; xxxvi., fig. 4.)

Edwardsia beautempsii, n. sp., Quatrefages, 1842, Ann. des Sci. Nat. (2), xviii., p. 69, pi. i., fig. 1.

Scolanthus callimorpha, n. sp., Gosse, . 1853, Ann. Nat. Hist. (2), xii., p. 157, pi. x.

Edwardsia callimorpha, Gosse, . . . 1860, Actiu. Brit., p. 255, pi. vii., fig. 7.

Edwardsia beautempsii, Andres, . . . 1884, Le Attinie, p. 92.

Edwardsia beautempsii, Pennington, . . 1885, Brit. Zooph., p. 177.

(For full bibliography consult Andres.)

Dr. A. Andres was the first to connect Mr. Gosse's species with that of
M. de Quatrefages ; in this as in other matters he has been followed by Mr. Pen-
nington. I have very carefully compared the published accounts, and with the
further advantage of being acquainted with the animal itself, and of having
access to a coloured drawing of Mr. Gosse, I have come to the opinion that the
forms are identical, and consequently Mr. Gosse's name must give place to that of
M. de Quatrefages. As a matter of fact, the Irish specimen is intermediate, so
far as colour and markings are concerned, between the types described by these
authors, and thus demonstrates their identity.

The following is a description of the single specimen we obtained : —
Form. — As in Mr. Gosse's description, the physa is short and rounded ; at
certain times it appears as if the apex was perforated.

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Colour. — Scapus, tawny orange ; cuticle friable, darker than the scapus ;
physa transparent, with a very slight pinkish tint ; capitulum pinkish, closely
speckled with minute white spots, and oesophagus shines through, of a madder
colour; madder-brown ring below the base of the tentacles interrupted by 16 short
white lines, 8 of which correspond with the insertion of the mesenteries, and the
other 8 are intermediate. Tentacles translucent, with numerous opaque, yellowish-
white irregular spots and ring-like marks, and a smaller number of dark rings ;
tips pinkish. Disc, pale, flesh-colour, finely spotted with madder ; circum oral
chevron ring, also madder-coloured ; a pair of dark madder spots about half way
up each of the radii of the primary tentacles. Mouth linear, pale colour, on a
small cone.

Dimensions. — Length, when extended, 48 mm. ; average diameter, 3 mm. ;
expanse of tentacular crown, 17 mm.

Locality. — Berehaven ; Bantry Bay, lOfaths., July, 16, 1886.

[Previous localities : — Weymouth ; Brixham ; Guernsey (Gosse). Is. Chansey,
Manche (Quatrefages), St. Malo, Roscoff (Grube)].

Edwardsia carnea, Gosse.
. (Plates xxxiii., fig. 15 ; xxxvi., figs. 5 & 6.)

Edwardsia carnea, n. sp., Gosse. . . 1856, Ann. Mag. Nat. Hist. (2), xviii., p. 219, pi. ix., figs.

1-4.

Edwardsia carnea, Gosse, .... 1858, Ibid (3), i., p. 418.

Edwardsia carnea, Gosse, .... 1860, Actin. Brit., p. 259, pi. vii., figs. 5, 6; pi. xii.,

fig. 3.

Edwardsia carnea, Hincks, . . . 1861, Ann. Mag. Nat. Hist. (3), viii., p. 363.
Edwardsiella carnea, Andres, . . . 1884, Le Attinie, p, 94.
Edwardsiella carnea, Pennington, . . 1885, Brit. Zooph., p. 178.

Localities. — Torquay, South Devon ; Tenby, South Wales (Gosse).

I am indebted to Mr. G. Y. Dixon for permission to publish the following
memorandum on this species : —

" April 24, 1887. — I have been studying the Edwardsia carnea that I got at
Babbacombe last week, and have come to the conclusion that it may most easily
be distinguished from E. timida by ridges that may be seen on its capitulum. I
have been able to observe them best when the animal is in the act of protruding
its disc and tentacles. Then if you look vertically down on the animal, viewing
it with a side light, you will see that each of the eight broad regions which make
up the capitulum is raised into a ridge running down its median line parallel to

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329

the direction of the region itself. As the animal expands these ridges disappear,
but they re-appear when it withdraws its disc and tentacles down into the
capitulurn. The shape of the capitulurn, too, in E. carnea, is more barrel-shaped
than in E. timida ; the opposite sides of the capitulurn in E. timida are always
parallel, while those of E. carnea are swollen like the sides of a cask."

Mr. Dixon obtained a couple of specimens from Mr. Gosse's own locality at
Petit Tor, near Torquay, and kindly gave me one, on which I have made a few
anatomical notes {vide p. 331).

Edwardsia timida, Quatrefages.
(Plate xxxvi., fig. 3).

Edwardsia timida, n. sp., Quatrefages, . 1842, Ann. des Sci. Nat. (2), xviii., p. 70, pi. ii., fig. 1.

Edwardsia harassi, n. sp., Quatrefages, . 1842, Ibid, p. 71, pi. ii., fig. 2.

Edwardsiella harassi, Andres, . . . 1884, Le Attinie, p. 94.

Edwardsiella timida, Andres, . . . 1884, Ibid, p. 96.

Edwardsia timida, G. Y. Dixon, . . 1886, Proc. Roy. Dub. Soc. (N.S.), v., p. 100, pi. vi.

Prof. H. Milne Edwards (1857, p. 286), and M. Fischer (1875, p. 203), merely
repeat M. de Quatrefage's description of these two species. Mr. Gr. Y. Dixon found
an Edwardsia near Dublin, which he describes very carefully and fully, after an
examination of eight specimens : these he regards as examples of E. timida, and at
the same time he unites M. de Quatrefage's two species, in which I also agree with
him. I may add that I have several times examined his specimens when alive, and
am able to corroborate his statements and support his conclusions.

Localities. — Is. Chansey, Manche (Quatrefages) ; Malahide, Co. Dublin (Dixon).

Edwardsia tecta, n. sp.
(Plates xxxiii., fig. 16; xxxvi., figs. 1 & 2).

Form. — Column elongated, thin ; divided into physa, scapus, and capitulurn ;
physa small, delicate, completely retractile within the scapus ; no terminal pore
can be detected in sections made through the apex of the physa ; scapus smooth,
with eight shallow longitudinal grooves, and without tubercles. The investment
is thin, wrinkled, translucent, and in preserved specimens quite loose, forming
a " membranous " tube within which the animal is withdrawn. Capitulurn delicate,

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completely rectractile ; tentacles eight in number, in the single specimen
examined.

Colour. — No accurate notes were taken of the living animal. The colouring
was certainly inconspicuous ; my belief is it was of a dirty-white colour, with the
disc and tentacles variegated with pale brown. Colour in preserved specimens
dirty yellowish-grey

Dimensions. — Contracted specimen 12 mm. long ; 2 mm. diameter.

Locality. — Nymph Bank, 52 faths., 28 miles south-west of Ballycotton, Co.
Cork ; and 70—80 faths., 5—8 miles west of the Great Skellig, off Co. Kerry.

Two specimens of this inconspicuous Edwardsia were examined ; it is certainly
distinct from any other British example of the genus, and, so far as I can gather
from the published accounts, equally distinguishable from other described forms.

The ectoderm of the retractable portion of the anterior extremity of the column,
the capitulum, and of the tentacles, consists of a layer of tall, ciliated, columnar
cells, with distinct nuclei ; the bases of those of the latter form a slightly pleated
sheath of longitudinal muscle fibres. Nematocysts are also present in the ectoderm
of the tentacles. The ectoderm of the scapus consists of shorter cells than the
foregoing, and their nuclei are more rounded ; they too are ciliated. The cells
are very granular, but their basal portion is clear, and contains numerous deeply
staining nuclei, which are much smaller than the nuclei of the epithelial cells. They
appear, however, only to occur in the extreme anterior region of the scapus.
Similar nuclei occur also in the ectoderm of the oesophagus and in the mesen-
terial filaments.

In the lower portion of the scapus the cells change somewhat in character;
large round nuclei, which are also found higher up, are more abundant : they
probably belong to the cells which secrete the investment. The ectoderm cells of
the oesophagus are very narrow ; those lining the oesophageal groove are shorter and
possess very long cilia ; the oesophageal ectoderm is ciliated, possesses numerous
nematocysts and glandular cells ; deeply staining nuclei are extremely abundant.

The endoderm does not call for special attention ; scattered about are deeply
staining masses, which are possibly glandular. The mesenterial filaments contain
gland cells in their upper portion only ; nematocysts occur as usual.

The mesogloea is very clear; in the body-wall it often contains foreign bodies,
which have become included by pressure from without.

The folds of the longitudinal retractor muscles of the mesenteries have a
remarkably leaf- or moss-like appearance. The folds are about ten in number,
either not at all or but very slightly forked, with the exception of the proximal
fold, which is large and branched in a manner which recalls a deer's antler. The
small proximal longitudinal muscle of the mesentery has a few moderately long
folds at right angles to its length, and which may be slightly bifurcated.

Haddon — A Revision of the British Actinia; .

331

In addition to the external differential characters which have already been
enumerated, it is possible to distinguish the various species of Edwardsia by
anatomical methods — at least such is the case for all the species I have been able to
examine. Unfortunately, as most of my material has not been sufficiently well
preserved, I am unable to give as precise an account as I should wish.

At present I can only speak definitely for the longitudinal retractor muscle of
the mesentery, and more especially for the small longitudinal muscle which is
present at the proximal extremities of the mesenteries. As the folds of this
endodermic muscle occur on each side of supporting lamina of the mesentery they
give a tree-like appearance to the muscle. I will refer to it as the parietal muscle.

In Edwardsia tecta (PI. xxxvi., fig. 2) the folds of the parietal muscle are about
half-a-dozen in number on each side, rather thick, of moderate length, and several
are more or less divided.

In E. heautempsii (PI. xxxvi., fig. 4) the folds of the parietal muscle number
about a dozen on each side ; they are relatively longer, and much more slender
than in the former species, and exhibit very little tendency to divide. There are
remarkable spaces in the mesoglcea of the body-wall, apparently filled with some
non-staining, coaguable fluid. These spaces open to the ectoderm by raised conical
orifices ; the ectoderm is also raised up over them, but I cannot find any opening
to the exterior. The pockets do not appear to be invaginations of the ectoderm, as
I cannot distinguish any epithelial lining ; the neck of the crater seems to be
plugged by ectodermal cells, the peripheral cuticle of which is entire. They occur
in the intervals between the mesenteries at the posterior end of the column. We
must await other and better preserved material before coming to a conclusion as
to their nature.

In E. carnea (PI. xxxvi., figs. 5, 6) there are some half-a-dozen short thick folds of
the parietal muscle rarely, and then but slightly bifurcate. The longitudinal
retractor muscle consists of a few (eight to ten or so) slightly branched folds. The
only specimen at my command cut very badly ; so I am unable to give further
histological details.

In E. timida the parietal muscle bears some resemblance to that of E. heau-
tempsii, but it is relatively smaller, and the mesoglcea of the proximal portion of
the mesentery is thinner ; in the latter species there is a lateral thickening and
extension of the mesoglcea, which gives a characteristic arrow-head appearance to
it in transverse section. In the present species the lateral folds are about ten in
number, and may be slightly divided; the proximal fold is usually complicated.
The rectractor muscle of the mesentery is very large and pear-shaped in section ;
the character of the folds can best be understood by a reference to the figure
(PI. xxxvi., fig. 3). The specimen examined was a male.

3 B2

332

H addon — A Revision of the British Actinias.

OTHEE DESCRIBED BRITISH EDWARDSIA :—

Edwardsia alhnani, n. sp., M'Intosh, . 1865, Proc. Roy. Soc. Edinb., p. 394 ; Marine Invert.

Fauna, St. Andrews, p. 37, pi. ii., fig. 3 ; pi. vii.,
figs. 1-4.

Edivardsia goodsiri, n. sp., M'Intosh, . 1865, I. c, p. 395 ; /. c, p. 38, pi. ii., fig. 4 ; pi. vii., figs.

5-7.

Locality for both of above, Saint Andrews.

On p. 262 of the " Actinologia," Mr. Gosse records the capture of an Edwardsia
by Canon Kingsley at Torquay, which he (Gosse) thinks is referrible to E.
beautempsii, Quatref. I have already stated my belief that E. calliniorpha, Gosse,
is that species. What then is this other form? The following is all the description
we have of it. While generally agreeing with E. calliniorpha in size and form, it
differed in the following points: — 1. The scapus was less opaque, more smooth
and lubricous, and studded with longitudinal rows of minute warts between the
invections. 2. The capitulum was clavate, proportionately longer, and of the same
colour as the scapus, a pale pinkish-buff, or light orange. 3. The tentacles were
fourteen in number, slightly uncinate or incurved, banded with dark buff. 4. The
disc was transparent and colourless, with a dark protruded mouth.

In the above particulars this Edwardsia agrees so well with the description
and beautiful figures of E. claparedii (Pane.) given by Professor Andres (" Le
Attinie," p. 90; pi. xi., pp. 1-5), that we may with justice, for the present, allocate
it to that species.

The following immature forms of British Edwardsia have been described : —
E. microps, Andres (Gosse), S. Devon (c. f. Gosse, " Actinologia," p. 252, and
Andres, "Le Attinie," p. 97); and E. sp. incert., Dublin Bay[(A. C. Haddon, 1886,
p. 527).

Halcampid^e (not of Andres).

Elongated Actiniae, with a vesicular base; six pairs of perfect mesenteries
present, including two pairs of directives; small imperfect mesenteries may be
absent or present in all or in some of the exocceles ; reproductive organs present
on all the mesenteries, or absent only on the sulcular directive mesenteries ;
tentacles simple, usually twelve in number, but may be twenty or twenty -four ;
one or two oesophageal (gonidial) grooves present or absent.

Mr. Gosse (1860, p. 227) erected the family Ilyanthidse to include Ilyanthus,
Peachia, Halcampa, Edwardsia, Arachnactis, Cerianthus, and Saccanthus. Prof.
Verrill (1864, p. 26) excluded the Cerianthidae. Profs. Allman (1872, p. 394),

Haddon — A Revision of the British Actiniae.

333

0. and R. Hertwig (1879, p. 124), and Andres (1880 a, p. 123) further detached
Edwardsia. Prof. R. Hertwig (1882, p. 92) still includes Ilyanthus, Peachia, and
Halcampa in the family, but Prof. Andres (1884, p. 240) confines the Ilyanthidse
to the genus Ilyanthus, the other two genera being types respectively of the
Siphonactinidae and Halcampidae.

I have framed the above definition so as to include Peachia as well as
Halcampa and Halcampella, for they appear in many respects to be allied genera ;
but Peachia may prove to be sufficiently distinct to necessitate a family of its
own. Till we have an account of the anatomy of Ilyanthus, it hardly appears
wise to associate it with the other forms.

Halcampa is the type genus of the family Halcampidae. Halcampella (Andres,
1883, p. 103) appears to differ solely in the fact that there are twenty-four
tentacles. Three species of Halcampa (II. ulbida, Ag., H. prodncta, Stimps.,
H. capensis, Verr.) have been described as possessing twenty tentacles ; the two
former (if they are distinct) have twenty longitudinal sulcations, evidently
corresponding to the insertion of the mesenteries. The more typical species of
Halcampa may have only six pairs of perfect mesenteries (II clavus of R.
Hertwig), or there may be six pairs of imperfect mesenteries, one pair in each
exoccele, as in the British species. In Peachia, however (vide page 338), there
are twenty mesenteries, six pairs of perfect mesenteries, and four pairs of imper-
fect mesenteries; but in this genus there are only twelve tentacles. Possibly the
three species first mentioned may prove to belong to a genus intermediate between
Halcampella and Peachia. The other recorded apparent anomaly in the number
of tentacles has already been referred to (p. 332) ; for H. microps (Gosse) is almost
certainly an immature Edwardsia.

BKITISH GENERA OF THE FAMILY HALCAMPID^E.
Halcampa, Gosse. Peachia, Gosse.

Halcampa, Gosse, 1858.

Halcampidae, with elongated vermiform body, divisible into capitulum, scapus,
and physa; the capitulum is retractile; no sharply-defined circular muscle;
oesophageal grooves present or absent ; tentacles twelve in number (? twenty in
some species); physa perforated by about twenty-four apertures at its apex; six
pairs of imperfect mesenteries present or absent (? four pairs in some species).

The adult Halcampa is a truly hexamerous Actinian ; but Dr. R. Hertwig, in
describing a form he identified as Halcampa clavus (Quoy and Gaimard) (1882,

334

Haddon — A Revision of the British Actinice.

p. 92), says it " is so clearly an intermediate form that I was for long dubious
whether I should treat of it under the Edwardsia? or Hexactinise." The reason for
this statement is found on p. 95, where he states: "As I was preparing a series
of sections through the one half of the physa of the larger specimen, it struck me
that three septa [mesenteries] (including the pair of directive septa) were not so
strong as the other septa, inasmuch as their longitudinal muscular cords became
sooner indistinct (pi. xiii., fig. 7). In the second smaller Halcampa, in which I
was able to make sections through the entire body, four septa were somewhat
smaller than the eight others." Prof. Hertwig then alludes to Halcampa fultoni,
but reverses Dr. Strethill Wright's account. The latter said, "Eight septa were
continued downwards to the lower extremity of the body, and had their free edges
bordered by a convoluted ciliated band, furnished with cnidae, or thread cells; the
intersepta (i.e. the four smaller mesenteries) bore no convoluted bands (Ann.
Mag. Nat. Hist. (3), viii., 1861, p. 132). Dr. Hertwig goes on to say: " All this
shows that an unequal development of the septa, and consequently a difference
in their morphological value, is not unusual in Halcampa. If we assume that the
eight stronger septa are homologous with the septa of Edwardsia, whilst the four
other septa are new formations, then the genus Halcampa would present us with
transition forms between the Edwardsia and the Hexactinise" (I. c., p. 95).

I have recently demonstrated (1887, p. 473) that the eight stronger mesen-
teries of the parastic larva, in Halcampa chrysanthellum are homologous with the
eight mesenteries of Edwardsia, and that not only in this respect, but also in the
presence of only eight tentacles, the larval Halcampa approaches the Edwardsiae.
There can be no doubt that Dr. Strethill Wright examined an older larva of
H. chrysanthellum than I obtained, as his specimen had twelve tentacles. On
referring to the rough diagram given in the paper quoted above, I find that his
four "intersepta" correspond with the four weak mesenteries which I have
figured (I. c, 1887, pi. xi., figs 6-8). It is unfortunate that Prof. R. Hertwig
gives us no information as to which of the mesenteries are stronger or weaker in
his smaller specimen ; probably they correspond to the sulcar elements of the
lateral pairs. His account of the mesenteries of the larger specimen does not
inform us as to which of the mesenteries are imperfect in addition to the pair of
directives, the only clue we have is his fig. 7, pi. xiii. The section includes a
single large mesentery on one side of the small directives, on the other side are
two large mesenteries with a small one between them. From their behaviour in
the British species of Halcampa, it is fair to assume that these are the sulcular
directive mesenteries : the other weak mesentery would correspond with the sulcar
member of the sulculo-lateral pair. If the remaining half followed the usual
arrangement in the genus, the mesenteries in this species would resemble in the
main those of the lower portion of the body of H. chrysanthellum.

Haddon — A Revision of the British Actinice.

335

BEITISH SPECIES OF HALCAMPA.

Halcampa cheysanthellum (Peach).
,, aeenaeea, Haddon.
clavus, Hertwig.

Halcampa chrysanthellum (Peach).
(Plates xxxv., figs. 1 and 2; xxxvi., fig. 7.)

Having a short time ago (1886, p. 1) critically discussed this species, there is no
need to repeat the bibliography there given. I find, however, that two synonyms
have been omitted from the bibliography (I. c. page 2) : Actinia chrysanthellum
should be inserted opposite to " Cocks, 1851," and Halcampa chrysanthellum
opposite to " Gosse, 1860." The ,, ,, marks which follow will then
be correct. I have recently found that Prof. K. Mobius, in 1873, records
Edwardsia chrysanthellum, from Kiel, 7-10 faths., mud ; and from Bulk
(near Kiel) 10^ faths., grey sandy mud and algae: he now regards this as the
correct specific name for E. duodecimcirrata, Sars, and of Meyer and Mobius.

From a note taken at the time this species appears to occur at Nymph Bank,
Co. Cork, 52^ fathoms, but I cannot now find the specimen, so there may be some
mistake in the identification; at all events the parasitic larval form was collected
by the tow net in Ballycotton Bay, Co. Cork, the previous night. Having
recently (1887, pp. 473-481; pi. xi.) given an account of the parasitic larva of this
species, nothing more need here be said.

Halcampa arenarea, Haddon.

(Plates xxxii. fig. 5 ; xxxiii., fig. 14 ; xxxv., fig. 3 ; xxxvi., figs. 8—10.

Halcampa arenarea, n. sp., Haddon, . . 1886, Proc. Eoy. Irish. Acad. (2), iv., Sci., p. 616. (The

specific name was erroneously printed " arenacea.")

Form. — Column divided into capitulum, scapus, and physa ; physa smaller,
globular, apparently without suckers, completely retractile ; scapus cylindrical,
even when extended, very contractile, provided with numerous long permanent
suckers, which adhere to grains of sand ; capitulum cylindrical when fully
extended, completely retractile. Tentacles — twelve, marginal, monocyclic, cylin-

336

Haddon — A Revision of the British Actiniae.

drical, obtuse, about as long as diameter of disc, usually so carried that the
endocoelic tentacles point forwards, the exocoelic being recurved.
Disc. — Flat ; mouth linear.

Colour. — Physa transparent, almost colourless; scapus a dull, pale, madder
brown ; capitulum translucent, dirty, flesh-colour : tentacles of same colour as
the capitulum, with four imperfect very pale-brown marks, and an M-shaped mark,
at the base of which the vertical limbs are situated on the sides of the tentacles ;
disc of same pale flesh-colour ; the twelve mesenteries appear as pale radiating
lines ; at the base of each tentacle is a pair of narrow, wedge-shaped, pale-brown
marks, the apices of which point towards the mouth ; between these and the mouth
is a lenticular pale-brown spot, which, with its fellows, form a ring round the
mouth, and separated from it by a short interval. Mouth brownish.

In another specimen the markings of the disc and tentacles were much less
distinct than in the former specimen; the axial line of the disc and the axial ten-
tacles were decidedly bleached, and the capitulum was translucent white, with white
bands.

Dimensions. — Length about 35 mm. ; in the ordinary condition it can contract to
about 18 mm. ; diameter variable, average about 7 mm.

Habitat. — South-west of Ireland, sand; mouth of Kenmare River, 38—44 faths.
(1885); mouth of Bantry Bay, 38 faths. (1886).

Halcampa clavus, R. Hertwig.

There is a record of a third British species of Halcampa which requires further
elucidation. On p. 674 of Capt. Tizard and Dr. J. Murray's paper on the "Explo-
ration of the Faroe Channel, during the summer of 1880, in H. M. S. (hired ship)
'Knight Errant/" (Proc. Roy. Soc. Edinburgh, Session 1881-82, vol. xi.),
Halcampa clavas is recorded from sounding 17, Station 2, lat. 60° 29' N., long.
8° 19' E., July 28, 375 faths., bottom temperature, 31°'0; that is, from the northern
(cold area) declivity of Wyville Thomson Ridge in Faroe Channel. Dr. Murray
informs me by letter that this specimen was identified by Dr. R. Hertwig. In
his "Challenger" Report, p. 92, Prof. Hertwig describes as Halcampa clavus an
Actinian dredged at Kerguelen (25-120 faths.) It is difficult to understand why
Dr. Hertwig did not adopt H. purpurea, Studer (1878, p. 545), as the name of this
species. Dr. Studer's specimens were obtained from the same locality as those
dredged by the 11 Challenger." This may or may not be identical with the Actinia
clavus of Quoy andGaimard, which the French naturalists found attached to a Medusa
in Bass' Straits ; but it appears to be extremely improbable that an antarctic species
of Halcampa should reappear in the cold area of the Faroe Channel, I can only

Haddon — A Revision of the British Actiniw.

337

conclude that Prof. Hertwig was struck by a superficial resemblance, and named
the specimen before he had made any anatomical investigation of it.

As Dr. Andres points out (1884, p. 97), Halcampa microps, Gosse (cf. " Actino-
logia," p. 252), is an immature Edwardsia, and he renames it E. microps.

A comparison of the figures on Plates xxxv. and xxxvi. will at once demonstrate
that it is perfectly easy to distinguish between the two British species of Halcampa
from transverse sections alone. The following are the most obvious dif-
ferences : —

1. The oesophagus in section is relatively to the diameter of the body very
much larger in H. chrysanthellum than it is in H. arenarea (PI. xxxv., figs. 1 & 3).

2. The marked difference in the pattern of the folds of the muscular
epithelium in the longitudinal muscles of the mesenteries. In H. chrysanthellum
the folds average ten or eleven in number, and are more open in character than in
H. arenarea : in the latter species there are usually some fifteen or so.

3. In H. chrysanthellum only six mesenteries bear generative products, these
being the pair of sulcar directives, and the two sulcular mesenteries of the perfect
lateral pairs ; the sulcular directives and the sulcar mesenteries of the perfect
lateral pairs being sterile (PL xxxv., fig. 2). All twelve mesenteries are fertile in
H. arenarea, apparently to an equal extent.

4. Suckers formed by outgrowths of the middle layer, coated by the ectoderm,
occur in H. arenarea (PL xxxvi., fig. 9), but are absent in the other species.

Other less marked distinctions can be discovered on submitting the various
organs and tissues to a rigorous examination.

Peachia, Gosse, 1855.

Halcampidse, with column divisible into capitulum, scapus, and physa; column
provided with numerous minute suckers ; the capitulum retractile ; no sharply
defined circular muscle ; a single deep oesophageal groove, which is continued
as a tube to nearly the posterior end of the body ; its oral end is produced
into well-marked, often complicated, lobes (the conchula), of which one basal and
two lateral elements can always be detected ; tentacles twelve ; physa perforated
by very numerous apertures in twelve longitudinal rows ; four pairs of short,
sterile mesenteries present, in addition to the six pairs of perfect fertile mesen-
teries, situated in the lateral and sulcar exocoeles ; longitudinal muscles of all the
mesenteries extremely well developed.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. V. 3 C

338

Haddon — A Revision of the British Actinias.

BEITISH SPECIES OF PEACHIA.
Peachia hastata, Gosse.

( undata (?), Gosse). (Probably immature form of above.)

( „ TRIPHYLLA, Gosse).

The last two species have hitherto only been recorded from the Channel
Islands.

Peachia hastata (Gosse).

This form occurs abundantly in a limited district in Dublin Bay. Mr. G. Y.
Dixon and myself have given (A. C. Haddon and G. Y. Dixon, 1885, p. 399) a
short account of the history and habits of this interesting Actinian. The only
accounts we have of its structure are — (1) a short notice by M. Faurot (1884, p. 756),
and an allusion to the oesophageal groove by Mr. Sedgwick (1884, p. 84), who
gives the only published figure (pi. ii., fig.. 6) of any anatomical details. The
figure represents an internal view of the upper portion of a partially dissected
Peachia (sp. not stated).

The accompanying diagram represents the arrange-
ment of the mesenteries and the general appearance
of their enormously developed longitudinal muscles.

There are six pairs of perfect (i. e. those which reach
the oesophagus) mesenteries arranged in the ordinary
manner. In each lateral and sulco-lateral exocoele
(inter-mesenteric chamber) there is a pair of small
imperfect mesenteries, these also possess relatively
very large longitudinal retractor muscles. Of the
twelve perfect mesenteries, the sulcar directives are Fl0. i._Diagrammltic section through
much larger than the others, and in the upper portion Peachia hastata.

of the body, below the oesophagus, bear the ciliated groove. The sulcular direc-
tives appear to be smaller than the four pairs of lateral mesenteries. All the
perfect mesenteries are fertile.

On a future occasion I hope to have more to say on this very interesting
Actinian, but I may here remark, that I have a sketch of a conchula of a specimen
not fully grown, which is practically identical with the woodcut Mr. Gosse gives
("Actinologia," p. 239) of his P. undata, and I am inclined to believe that the latter
is but a half-grown P. hastata.

Several larval Actiniae, together with the Leptomedusae, on which they were
parasitic, were given to me by my friend, Prof. W. C. M'Intosh, who obtained

Haddon — A Revision of the British Actiniw.

339

them at St. Andrew's, Fife, Scotland, in 1887. The Actinise attach themselves
to the upper or under surface of the bell, or to the margin, or to the gastric region
of the Medusas. (M'Intosh, 1887.)

The Actiniae from St. Andrew's are of slightly different ages : the youngest so
exactly corresponds to the stage of Halcampa chrysanthellum previously described
by me (1887, p. 473), that a further description would be superfluous. The
slightly older larvae are larger, the tentacles are longer, and new tentacles are
making their appearance in the lateral endocceles. I am not yet in a position to
state whether there is any particular order in their development.

At first sight these young Actiniae bear an unmistakable resemblance to the
larvae of Halcampa chrysanthellum both externally and anatomically; so we may
confidently consider them to be closely allied. The presence of twelve mesen-
teries precludes their being Edwardsiae. The genera Peachia and Ilyanthus are
usually associated with Halcampa: of the second of these I can say nothing, as it
has never been anatomically described ; besides, it is quite a rare form ; but our
larvae are decidedly common. We then narrow the question to Halcampa and
Peachia. Only two British species of Halcampa are known — H. chrysanthellum of
North European distribution, and H. arenarea (ante, p. 335) from the south-west
of Ireland. Of this only two specimens have been obtained. I have made sections
through three parasitic larvae of H. chrysanthellum, and am therefore well acquainted
with it, and, although they agree perfectly with the forms from St. Andrew's in
their general appearance and structure, still there are distinctions in their
histology which cannot now be gone into. One point, however, deserves special
mention, and that is the appearance of the longitudinal retractor muscle of the
larger mesenteries. In the earlier stages of H. chrysanthellum the muscle is
relatively more extended than in the adult, but the distal plications are of
considerable length, and decidedly recall those of the adult. In a later stage this
is naturally still more marked. The corresponding muscles in the St. Andrew's
specimens is much less conspicuous; it extends for a greater distance across the
mesentery, consequently the plications are more numerous, but, on the other hand,
they are very much shorter and simpler than in H. chrysanthellum.

In transverse sections through Peachia hastata I find that the retractor muscles
are greatly developed, forming a regular close-set fringe to the border of the
mesentery, and thus constituting a type of muscle very different from the
reniform section of the retractor in Halcampa. My material is at present
insufficient to enable me to make a definite statement, but there is nothing in the
character of the longitudinal muscles of the mesenteries antagonistic to the view
that these are the young of Peachia hastata. The latter species, according to
Prof. W. C. M'Intosh, is common in the neighbourhood. I would further point
out that the larvae from St. Andrew's, stage for stage, are decidedly larger than

3 C 2

340

Haddon — A Revision of the British Actinice.

those of the Halcampa which occurred to me : this would also correspond with the
greater size of the adult Peachia over that of Halcampa.

A preliminary account of the above, with rough diagrams, has recently been
published by myself (1888 (A), p. 281 ; (B), p. 256).

The localities for P. hastata are — north of France, south of England, east
of Ireland, and east of Scotland. The unique specimen of P. undata came
from Herm, Channel Islands.

The remaining British species is Peachia triphylla, Gosse {cf. Gosse, Actin-
ologia, p. 243, and Andres, Le Attinie, p. 109).

Actinia cylindrica, Eeid (1848, Ann. Mag. Nat. Hist, (n.s.), l, p. 34), was called
Peachia cylindrica by Mr. Gosse (" Actinologia," p. 245), and Halcampa cylindrica
by Dr. Andres (" Le Attinie," p. 105). Mr. G. Y. Dixon and myself (1885, p. 400)
have discussed its identity with P. hastata. As A. cylindrica was at the time
pre-occupied, Mr. Gosse's name stands.

The synonymy of the Actiniae which are found parasitic on various Medusae,
and which have been referred to the genera Bicidium, Philoniedusa, Halcampa,
and Peachia, has recently been discussed by me (1887, p. 473), and need not be
here repeated.

Ilyanthus.

I have no knowledge of this genus.

Gonactinia.

Although not recorded as British, I propose to give a brief account of
Gonactinia prolifera, Sars, as it appears to constitute an interesting link in the
series of forms we are now considering.

Gonactinia prolifera, Sars.

Actinia prolifera, n. sp., M. Sars, . . 1835, Beskrivelser og Jagttagelser over nogle maerkelige

eller nye i Havet ved den Bergenske Kyst levende
Dyr, &c, Bergen, pp. 3, 11, pi. ii., fig. 6.

Gonactinia prolifera, M. Sars, . . . 1851, Nyt. Mag. f. Naturvid., vi., p. 142.

Gonactinia prolifera, Koren, . . . 1859, Nyt. Mag. f. Naturvid, ix., p. 93.

Gonactinia prolifera, Andres, . . . 1884, Le Attinie, p. 362.

Gonactinia prolifera, Blochinann andHilger, 1888, Morph. Jahrb., xiii., p. 385, pis. xiv. and xv.
Habitat. — Coasts of Norway, from 2 to 20 faths.

Very recently Drs. Blochmann and Hilger (1888) have given a careful
anatomical description of Gonactinia prolifera, Sars, and of its remarkable anular

Haddon — A Revision of the British Actiniw.

341

method of reproduction by means of transverse fission or strobilisation. These
authors find that there are sixteen mesenteries, eight of which reach the oesophagus
(" macrosepta "), and .the other eight do not (" microsepta " ). Two pairs of
directive mesenteries are present. Starting from what they identify as the
dorsal (sulcular) directives, there are on each side a pair of microsepta. (?) Then
follows a macroseptum, which, below the oesophagus, bears the "generative
organs;" then a microseptum; next again a "fertile" macroseptum, followed by
a microseptum; and lastly, there are the two sulcar ("ventral") directives.

The longitudinal, or retractor, muscles of the mesenteries are arranged in such
a manner that the two microsepta on each side of the dorsal directives form a
pair : two other pairs are formed by a macroseptum and a microseptum respec-
tively. The accompanying diagram illustrates these facts.

Fig. 2. — Gonactinia prolifera (after Blochman and Hilger).
A, half a transverse section below the oesophagus ; B, transverse section through the oesophageal region.
(For lettering, see explanation of Plate xxxiv.)

Two oesophageal grooves are present. There are sixteen tentacles in two rows
of eight each. " Septalstomata " or perforations in the mesentery appear to be
absent. Acontia are also wanting. Length when extended 5 mm.

Drs. Blochmann and Hilger point out that we have in Gonactinia two
mesenterial systems which may be compared together, but are inversely
orientated. The one consists only of macrosepta, the other solely of microsepta.
Each of them exhibits, in its own disposition of muscles, that which one finds in
the Edwardsiae. Later on they state that this Actinian cannot be placed in Prof.
R. Hertwig's system ("Challenger" Report). Perhaps it hadjbetter be ranged near
the Zoan these; it agrees with these in the presence of partition walls of two kinds,
but is sharply separated from them by the possession of two oesophageal grooves.
At all events a new tribe must be erected for it.

342

Haddon — A Revision of the British Actiniae.

These authors' comparison of the mesenteries of Gonactinia with those of
Edwardsia calls for remark. The agreement of the " macrosepta " with the
mesenteries of Edwardsia is suggestive, but nothing appears to be gained by
turning the animal round and seeing a similar agreement in the 11 microsepta."

I would rather suggest a comparison with the arrangement of the mesenteries
which obtains in the young of several other Actiniae (see p. 350). By comparing a
diagram of the latter (PL xxxvn., fig. 7) with the one of Gonactinia (p. 341, fig. 2)
it will be seen that there are only two points of difference — (1) the Halcampa larva
has only one oesophageal groove (the ventral), and (2) the addition of a pair of weak
mesenteries (microsepta) on each side of the pair of dorsal directive mesenteries.
The lateral strong mesenteries in Gonactinia are alone " fertile," in Halcampa
chrysanthellum (PI. xxxv., fig. 1) these, with the ventral directive mesenteries, bear
the gonads. It is questionable whether the possession of a mesenteric filament by
the weak mesentery, between the two "fertile" mesenteries in Gonactinia, is of
any special significance.

A pair of very small secondary imperfect mesenteries occur in the inter-
mesenterial chambers of Halcampa chrysanthellum and H. arenarea, as in most
other Actiniae, but not in H. clavus (R. Hert., (?) of Q. & G.). The sulculo-lateral
pairs of similar mesenteries in Gonactinia may for the present be regarded as
being the equivalent of these, but of which only two pairs are developed. We
have just seen that in Peachia hastata the lateral and sulco-lateral pairs of
imperfect septa are alone present, so the occurrence of only sulculo-lateral pairs is
not very anomalous. The only unique feature in this Actinian is the faculty of
a sexual reproduction by means of transverse fission.

It will be seen from the above that I have mentioned the presence of gene-
rative organs in Gonactinia with doubt. An inspection of figure 2 will show that
the character of what have been identified as the testes is very different from the
testes as figured by the Brothers Hertwig, or in the accompanying plates (PI. xxxv.,
figs. 2 & 6 ; PI. xxxvi., fig. 7) ; and indeed from any Actinian generative
organ with which I am acquainted. These bodies, however, are so similar in
appearance and size to the commensal unicellular algae (Zooxanthellae), that Drs.
Blochmann and Hilger must adduce conclusive evidence of their sexual nature
before their view can be accepted. It is not unusual to find the algae crowded in
the same four mesenteries of the young of Cereus pedunculatus in the stage corre-
sponding to that of the figured Gonactinia.

The minute size of Gonactinia is suggestive of immaturity, as adult Actiniae
are rarely very small. The arrangement of the mesenteries, as will be seen from
what follows, also supports the view, that this may after all be an immature form :
this is also confirmed by the character of its histology and the feeble development
of the mesoglcea.

Haddon — A Revision of the British Actinia?.

343

I am not prepared to say of what form Gonactinia is probably a larval stage,
but would venture to suggest an investigation of the development of Anemonia
sulcata (Penn.) = (Anthea cereus, Auct), and of Actinopsis flava (Dan. & Kor.), the
young forms of which are undescribed. An anatomical investigation of the latter
species would be particularly interesting.

Zoanthejs.

Actiniae, with numerous perfect and imperfect mesenteries ; two pairs of directive
mesenteries, of which the sulcar are perfect and the sulcular are imperfect. A pair
of mesenteries occur on each side of the sulcular directives, of which the sulcular
moiety is perfect and its sulcar complement is imperfect ; a similar second pair
occurs in one section of the group (Zoanthus), or the second pair may be composed
of two perfect mesenteries (Epizoanthus). In all the remaining pairs of mesenteries
this order is reversed, so that the perfect mesentery is sulcar and the imperfect
sulcular. The latter series of mesenteries are bilateral, and arise independently
{i. e. neither in pairs nor symmetrically on each side) in the exoccele on each side of
the sulcar directives, in such a manner that the sulcular are the oldest and the
sulcar are the youngest. The perfect mesenteries are alone fertile. A single
sulcar oesophageal groove is present. Animals usually forming colonies ; body-
wall usually traversed by irregularly-branching ectodermal canals, and rendered
rigid by grains of sand.

Prof. Dana (1846), and later, Dr. Andres (1877), and the Brothers Hertwig
(1879), showed that the mesenteries of the Zoanthese were arranged on a different
plan from those of other Actinias, and demonstrated the occurrence of alternate
perfect and imperfect mesenteries ; but Prof, von Koch (1880) was the first to
elucidate this arrangement in Zoanthus [Palythoa) axinellce. Prof. R. Hertwig's
" Challenger" Report was published in 1882, and threw much further light
upon the anatomy of the Zoanthese. Shortly afterwards Dr. Gr. Miiller (1883)
published his dissertation, in which he more or less fully describes fourteen species
of Palythoa and Zoanthus. The last Paper on the subject is one by Dr. A.
Erdmann (1885).

In this very important Paper Dr. Erdmann describes two species of Zoanthus,
five species of Epizoanthus, three species of Palythoa, two species of Corticifera,
one of Sphenopus, and an unnamed new genus : of these fourteen species only one,
Palythoa axinellce, Schmidt, is fully identified. The main facts relating to the
arrangement of the mesenteries are as follows : —

Two kinds of mesenteries are present in the Zoanthese —

1. Larger, or 11 macrosepta," bearing mesenterial filaments and generative

Haddon — A Revision of the British Actiniae.

organs, which reach the oesophagus throughout its entire length, and are therefore
" perfect."

2. Smaller, or " microsepta," without mesenterial filaments and generative
organs, which, not reaching the oesophagus, are "imperfect."

A macroseptum and a microseptum together constitute a pair of mesenteries, as
the sides which face each other bear a longitudinal muscle. Only two pairs form
an exception, these are the pairs of directive mesenteries, situated one at each of
the long axis of the oesophagus, and whose longitudinal muscles are on opposite
sides of the mesenteries.

The oesophagus possesses but one oesophageal groove, the directive mesen-
teries of this pole being macrosepta, whereas those of the opposite side are
microsepta.

In Zoanthus the pairs of mesenteries are arranged in two series — (a), on each side
of the micro-directive mesenteries, and starting from them the first two pairs consist
each first of a macroseptum and then of a microseptum ; (b), the third and suc-
ceeding pairs each consist first of a microseptum, and then of a macroseptum, thus
the pair of macro-directive mesenteries lie between two macrosepta. In Epi-
zoanthus the arrangement is the same, except that the second pair of mesenteries
is composed of two macrosepta, instead of a macroseptum and a microseptum. (See
Diagrams, PI. xxxvu., figs. 1 & 2.) Thus, in addition to the bilateral symmetry,
which is discernible in all the Actiniae, although superficially they appear to have
a typical radial symmetry, we have in the Zoanthese a division line at right angles
to the sagittal axis, which demarcates the regions of the pairs of mesenteries just
alluded to.

Prof. R. Hertwig has termed the micro-directive mesenteries "dorsal," and
the macro-directives "ventral," and in this he is followed by Dr. Erdmann. As
the former zoologist says, " We can therefore divide the ordinary pairs of ' septa'
(mesenteries) into two different regions ; in the one (the larger or ventral region)
the ventral septa of the single pairs are macrosepta, and the dorsal septa are
microsepta, whilst in the other (the dorsal region) the reverse is the case, and the
dorsal septa are macrosepta" (" Challenger " Report, p. 110).

From the foregoing description it will be seen that there are two types of
arrangement — the one in which the sulcular ("dorsal") region is separated
from the sulcar ("ventral") by two imperfect mesenteries (PI. xxxvu., figs.
1 & 2) ; and the other in which the two regions are divided by two perfect
mesenteries: the former type is termed by Dr. Erdmann the " microtypus," the
latter the " macrotypus."

I object to use the terms "macro-" and " micro-septa," not only because they
are hybrid words, but on account of the use of the word "septum," which, as I
have previously stated, should be retained for the calcareous partitions of the

Haddon — A Revision of the British Actinia'.

345

corals. There is, moreover, no need to introduce a new term when we already
possess the equivalent in "perfect" and "imperfect" mesenteries.

As Dr. Erdmann also points out, in Actinias the development of the mesenteries
falls into two periods. The first, in which there are six perfect pairs, including the
two pairs of directives. In the second period, in the majority of Actiniae, the other
mesenteries successively appear in pairs in the centre of each intermesenterial
chamber (exoccele) ; but never in an intramesenterial chamber (endoccele). These
constitute the mesenteries of the second, third, &c, order.

It is in the second period that the order of origin of the mesenteries is different
in the Zoantheae ; for here the new mesenteries are formed only in the inter-
mesenterial chambers which lie immediately on each side of the sulcar (" ventral ")
directive mesenteries. The perfect mesenteries and imperfect mesenteries are
developed independently of each other, and not necessarily symmetrically. From
this it follows that — taking the sulcar region into consideration only — the most sul-
cular mesenteries are the oldest ; those nearest the sulcar directive are the youngest,
the mesenteries appearing singly, and not in pairs, and, lastly, there may be more
on one side than on the other (see PI. xxxvu., fig. 3).

We may put this another way, by saying that in the majority of Actinias the
new pairs of mesenteries appear radially in all the exocceles, whereas in the
Zoantheae they appear laterally in the sulcar exocceles.

At a very young stage, that is, in the first period, only the two pairs of
directives, and the sulcular pairs of mesenteries are present, but the distinction
noted above still obtains. (See diagrams, PI. xxxvu., figs. 4 & 5). Dr. Erdmann
terms these young stages, respectively, the " microgrundform," and the " macro-
grundform."

We are justified in assuming that the sole distinction between these two types
is, that in the "macrotypus" the second lateral perfect mesentery (that is, the sulcar
element of the sulco-lateral pair of the ground-type) on each side has developed
into a perfect mesentery. If this be so, Prof. Hertwig was mistaken in supposing
that in this group two imperfect mesenteries are wanting between the sulculo-
lateral pair of perfect mesenteries.

We are now in a position to discuss the probable relationships of the Zoantheae.
On comparing a diagrammatic section, through a young microtype form (e. g.
Zoanthus) with a similar section through a larval Halcampa, we find an absolute
identity in the disposition of the mesenteries, with the single exception of the
sulcular directives, which are imperfect in the Zoantheae, but perfect in Halcampa,
although both in the young form and the adult they are perceptibly weaker
than the other eight perfect mesenteries (diagrams, PI. xxxvu., fig. 7, A & B). The
sulcar oesophageal groove alone is present, and, lastly, in the adult, H. chrysan-
thellnm, it is only those mesenteries which correspond with the perfect mesenteries

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART V. 3D

346

Haddon — A Revision of the British Actiniee.

of, say, Zoanthus, which are fertile, and it must be remembered that only the
perfect mesenteries of the Zoanthea? are fertile.

Accepting the arrangement of the mesenteries as a clue to affinity, and, as a
matter of fact, we have little else to guide us, we may safely assert the relationship
of the young Zoan these with the young of several different forms of Actinias, as I
shall show. The adults constitute a very distinct subdivision of the Actinia3, owing
to the unique method in which the new mesenteries make their appearance. The
very general possession of ectodermal canals in the body-wall and of asexual repro-
duction by means of buds from a stolon serve to accentuate their distinctness.

I have not yet had time to sufficiently study the British species of Zoantheae
from an anatomical or from a synonymic point of view.

DEVELOPMENT OF ACTINIAE.

With the exception of an important Paper by Prof. H. de Lacaze Duthiers
(1872), very little has been done to elucidate the developmental history of Actiniae.
So far as they go the researches of the above author are most precise, and are
illustrated by beautiful figures. The facts elucidated are very remarkable, and are
not at all what would, a priori, be expected to occur in a hexamerous Actinian.
The investigations mainly concern the order of appearance of the mesenteries
and tentacles : the former will first occupy our attention.

Prof, de Lacaze Duthiers studied the following species: — Actinia equina, Cereus
vedunculatus = {Sagartia bellis); Cylista undata = (S. troglodytes); and Bunodes
verrucosa — (B. gemmacea).

The following brief abstract refers to the first species: —

Actinia equina.

1. The cavity (ccelenteron) of the larva is divided into two unequal chambers
by two small mesenteries which arise transversely to the long axis of the oesopha-
gus. The larger chamber will be referred to by a', the smaller by a (PI. xxxvu.,
fig. 8).

2. A second pair of mesenteries is next formed in the chamber a', dividing it
into a larger terminal chamber (#'), and a lateral small chamber (b) on either side
(PI. xxxvu., fig. 9).

3. In the next stage chamber a is similarly divided into a terminal chamber (a),
and into a pair of lateral chambers (c). Following so closely upon this as to
almost occur at the same time, the chamber b of each side is subdivided into b
and d by the formation of mesentery No. 4 (PI. xxxvii., fig. 10).

Haddon — A Revision of the British Actinice.

347

The first and second pairs of mesenteries to appear are also the first which reach
the oesophagus : shortly later the third and fourth pairs also join (PL xxxvn., fig. 11).

4. The chambers d are next divided into d and e by No. 5 mesentery, and
this is closely followed by the division of c into c and / by the 6th pair of
mesenteries (PI. xxxvu., fig. 12). These two new pairs of mesenteries are at first
quite short, and do not possess the mesenterial filaments which characterise the
other mesenteries. Of the latter, the first pair to appear still maintains its pro-
minence by having very large craspeda: they were also the first mesenteries to
obtain them (PI. xxxvu., fig. 13).

Later, the fifth and sixth pairs of mesenteries reach the oesophagus, so that
there are now twelve perfect mesenteries, which fall into the ordinary Actinian
arrangement of two pairs of directives and two pairs of lateral mesenteries. It
must be borne in mind, that in the description of the order of the mesenteries,
the "pairs" spoken of merely referred to the synchronous appearance of two
corresponding mesenteries on each side of the axial line, and not two pairs of
complementary mesenteries.

At a later stage each exoccele is divided by a pair of mesenteries in the usual
manner, but in a slightly older larva, figured by Prof, de Lacaze Duthiers, the
two exocceles on each side of the axial endocoele a' have each originated a pair of
small mesenteries.

Concerning the third stage in the order of appearance of the mesenteries, our
author says {I. c, p. 331) : " One may see from the preceding paragraph, that it is
difficult to establish the succession of the partitions of the third and fourth for-
mation. It is only when they are well marked, that one can recognize that the
one is more developed than the other. It results from this — an obviously very
remarkable fact — that the period when the number six occurs is very quickly passed
over, very fugitive ... If then the period of four chambers is very evident and
easy to establish, the period of the number of eight is not less so."

It is during the octoradiate stage that the tentacles first appear. The earliest
to appear sprouts from the terminal chamber a', and until the twelve-rayed stage
has become well established this tentacle is markedly larger than the others. Of the
remaining seven tentacles, those corresponding to the median lateral chambers (d)
are next largest. The axial tentacle a and the other four tentacles are much
smaller, being scarcely more than tubercles (PI. xxxvu., fig. 14, A, B, & Cj.

In the next stage, the axial tentacles (a' and a) and the three central lateral
ones (d, e, f) are large and of the same size, except a', which is still the largest :
the remaining four tentacles, corresponding to the exocceles on each side of the
directives, remain rather small.

The order of development of the mesenterial filaments is as follows : — (1) The
first pair of mesenteries; (2) the fourth pair; (3) the second and third pair

3 D 2

348

Haddon — A Revision of the British Actinice.

practically simultaneously ; (4) the fifth and sixth pairs of mesenteries acquire
their craspeda somewhat later.

These three organs — mesenteries, tentacles, and craspeda — appear in pairs
relative to the axis of the body, and not in the least corresponding to the paired
radial symmetry of the adult. In other words, the early larva are bi-laterally
symmetrical, and it is only on the completion of the stage with twelve perfect
mesenteries that the young definitely acquires the radial symmetry of the adult.
The tentacles, however, continue to develop in an apparently anomalous manner,
which need not now detain us : on the completion of the number twenty-four they
are arranged in the cycles typical of the Actinias, viz., 6 + 6 + 12. Another
period of irregular appearance occurs, but when the forty-eight stage is established,
the radial symmetry again becomes predominant, and we have 6 + 6 + 12 + 24.
In this and in the preceding stage the tentacles do not appear in the order which
their size or their cycle would indicate: thus we have the tentacles of a sextant
arranged as follows : —

Cycle, .

I.

IV.

III.

IV.

II.

IV.

III.

IV.

I.

Appear.,

1

4

4

3

3

2

4

4

1

The marginal spherules which characterise this species appear at the twelve-
rayed stage.

The first two mesenteries to appear, that is those which primitively divided
the embryo into moieties, can, by their size, be continued to be recognized,
until the period when the young Actinia has twenty-four tentacles : thus it is
possible up to this stage to recognize the elements dependent on each of the two
primitive moieties.

Cereus pedunculatus (Sagartia hellis).

The formation of the mesenteries and tentacles in this form exactly recapitu-
lates that of Actinia equina. At the stage of twenty-four tentacles, acontia are
formed by the edges of the two mesenteries which first make their appearance,
becoming detached and floating freely in the ccelenteron. As in the above
example, the same mesenteries first acquire craspeda, very shortly afterwards the
fourth pair also develop them. This preponderance of the first four filaments is
early apparent, and persists until the twelve-rayed stage is passing away, when
the directive mesenteries acquire their mesenterial filaments, wbich soon outstrip
the others in size.

Haddon — A Revision of the British Actinice.

349

Cylista undata (Sagartia troglodytes).
The development of this Sagartid precisely resembles that of the foregoing.

Bunodes verrucosa (B. gemmae ea).

The order of development of the mesenteries and tentacles is the same as
above, but it appears that Bunodes remains longer in the octoradiate stage than
the preceding species (PI. xxxvn., fig. 15). As before, this number eight is
decomposable into three and five, on account of the position of the first pair of
mesenteries. The four new tentacles to complete the twelve arise from the
chambers c and e (compare diagram, PI. xxxvn., fig. 16).

The mesenterial filaments at first appear on the two oldest pairs of mesenteries,
i. e. 1 and 2 : later they occur on the mesenteries of the fourth age (PI. xxxvn.,
fig. 16).

Professor A. Kowalevsky has published some observations on an unde-
termined species of Actinian. The first two mesenteries appear at the same
time that the lips of the blastopore are invaginated, to form the oesophagus
(stomatodseum). A pair of mesenteries then appear in each of the two chambers,
into which the ccelenteron is divided by the first pair. So far the order agrees
with that described above for Actinia equina, but instead of a pair of mesenteries
arising laterally, an unpaired mesentery is formed in one axial chamber, and
shortly afterwards one arises in the opposite axial chamber: thus a stage with
eight mesenteries is also developed.

The Brothers Hertwig (1879) describe three stages in the development of
Adamsia diaphana, the earliest of which already possessed twelve mesenteries
(diagram, PI. xxxvu., fig. 17, A & B). In their second stage the outer mesenteries
of the four short lateral mesenteries have grown considerably, and developed their
longitudinal muscles. They are now seen to be the complements of the four perfect
lateral mesenteries, and later they too reach the oesophagus, and complete the six
pairs of primary perfect mesenteries. In the last stage the pairs of mesenteries
of the third and fourth cycle have appeared in the exocceles in the ordinary
manner.

The only account we possess of the development of the mesenteries in Edwardsia
is the preliminary publication of some drawings in the " Selections from
Embryological Monographs " (1884), of an unpublished Paper by Dr. E. L. Mark.
The form studied was, perhaps, Edivardsia lineata, Verr., which, in its earlier
stages, is parasitic in the Ctenophore Mnemiopsis leidyi. Two mesenteries first

350

Haddon — A Revision of the British Actinias.

appear: these are the sulco-lateral, or, according to the ordinarily received termino-
logy, the ventro-lateral. The right sulco-lateral mesentery ends somewhat abruptly
before reaching the aboral pole. In a transverse section made at an early stage
depressions in the surface of the endoderm show the places where the mesenteries
will appear. The depressions corresponding to the sulculo-lateral mesenteries
are most evident ; those of the sulcar pair are less distinct, but those of the
sulcular pair are not indicated. In a slightly later stage the sulcular mesenteries
have made their appearance, the sulco-lateral are relatively very large, and their
terminal filaments are very conspicuous. The other six mesenteries are quite
small, and appear to be uniform in size. In the upper portion of the body all
eight mesenteries reach the oesophagus, and the rudiments of their longitudinal
muscles are visible. These have the arrangement characteristic of Edwardsia.

In the brief abstract just given of Prof, de Lacaze Duthiers' researches, his
account has been given without comment, and his numeration of the mesenteries
and lettering of the mesenteric chambers has been adhered to. According to the
system of nomenclature which I now propose, the development of the mesenteries
is as follows: — 1. Sulcular sulco-laterals ; 2. sulcular directives; 3. sulcar
directives; 4. sulcular sulculo -laterals; 5. sulcar sulculo-laterals ; 6. sulcar sulco-
laterals. The chambers being a, sulcar endoccele ; a' sulcular endoccele ; b, sulcular
exoccele ; c, sulcar exoccele ; d, sulculo-lateral endoccele ; e, lateral exoccele ; /,
sulco-lateral endoccele.

When these researches were published attention had not been called to the
importance of the position of the longitudinal retractor muscle of the mesenteries
in the morphology of the Actiniae, and Prof, de Lacaze Duthiers makes no mention
of this structure. The identity of the general disposition of the mesenteries and
their relative size had led me to regard the fourth stage of the above account as
being in every way comparable with the larva of Halcampa chrysanthellum which I
have previously described (1887). At my suggestion, my pupil, Mr. Francis
Dixon, has commenced an investigation upon the embryology of Actinia?, and he
has kindly permitted me to anticipate some of the results he has arrived at. Mr.
Dixon has cut transverse sections of larva? of Prof, de Lacaze Duthiers' three
types, viz. Actinia equina, Cereus pedunculatus, and Bunodes verrucosa, with the
anticipated result. In these representative species of three different families of
Actinia?, the development of the mesenteries is similar in all, both as regards
the order of their appearance and the disposition of their muscles, and they
are also identical with those of the larva of Halcampa (I am now confining
myself to the first six pairs of mesenteries, which probably, alone, are of primary
importance).

The only definite observation which is opposed to this statement is that of the
Brothers Hertwig (1879). Their account of the disposition of the mesenteries in

Haddon — A' Revision of the British Actinice. 351

Adamsia diaphana has already been given. In order to bring Prof, de Lacaze
Duthiers' description into harmony with their observation, they assume that the
French zoologist has mistaken the order of appearance of bis second and fourth
pairs of mesenteries. By interchanging these two numbers, and by supposing
that the longitudinal muscles of the first and second (according to them) mesen-
teries face one another, they bring the older account into accord with the eight
perfect mesenteries of their first stage. With all due deference to the distinguished
German zoologists, it seems to be somewhat unfair to throw doubt upon the very
careful and minute investigations of Prof, de Lacaze Duthiers, and it affords me
great pleasure to be able to corroborate and extend the observations of the
illustrious French savant. Adamsia diaphana is a Sagartian, as is also Cereus
pedunculatus, and it requires to be studied anew, especially its earlier stages.

GENERAL CONSIDERATIONS.

The following deductions, based upon embryological and anatomical evidence,
appear to be warranted by the present state of our knowledge : —

1. In larval Actiniae two mesenteries arise at right angles to the long axis of
the oesophagus, and divide the archenteron (ccelenteron) into two chambers.

These two chambers are unequal in Actinia equina, Cereus pedunculatus, Cylista
undata, Bunodes verrucosa, and Edwardsia lineata,{Y) and possibly also in Cerianthus
membranaceus, and in Actinia sp. (Kowalevsky).

2. A pair of mesenteries appears in the larger of the two primitive chambers
of the ccelenteron. Apparently this stage is common to all investigated Actiniae ;
but as no observations have been made on the mesenteries of Cerianthus beyond
the first stage, it must be left out of consideration.

3. A third pair of mesenteries develops in the smaller of the two primitive
chambers. Immediately afterwards another pair of mesenteries appears.

In the first four species the fourth pair of mesenteries arises between the first
and second, that is, in the lateral chambers of the larger of the primitive divisions
of the ccelenteron ; but in Edwardsia lineata (?) the new pair appears within the
single or terminal chamber of the same division. Prof. Kowalevsky's account of

352 Haddon — A Revision of the British Actinice.

the development of the seventh and eighth mesenteries cannot be brought into
harmony with the preceding.

A short resting stage now occurs in which eight mesenteries are alone present,
and the corresponding chambers of the ccolenteron are produced into eight
tentacles.

This appears to be a characteristic phase in the development of all the Actinias
hitherto studied, with the exception of Ceriantlms. There is now evidence to
support the conclusion that in most, and probably in all other larval Actinia?, these
eight mesenteries are homologous with those of the Edwardsise. In other words,
such forms as Halcampa, Actinia, Cereus, JBunodes, and probably many, if not all
other sea-anemones (except Cerianthus), pass through a larval stage, which is
permanently retained in the adult Edwardsise.

4. The next stage is characterized by the practically simultaneous development
of two pairs of mesenteries : these for some time remain imperfect : their
longitudinal muscles face those of the first and fourth mesenteries re-
spectively.

This condition exists in Gonactinia prolifera, and practically permanently in
the Zoanthese, although in the Epizoanthus group the equivalent of the sixth pair
of mesenteries reach the oesophagus. The terminal zone of mesenteric development
is a special feature added on to the above arrangement. This fourth stage occurs
for a long time in the larva of Halcampa, but it is more rapidly passed over in the
four species described by Prof, de Lacaze Duthiers.

5. The fifth and sixth pairs of mesenteries now reach the oesophagus, and
constitute the ground or fundamental form of the typical hexamerous Actinias.
Twelve tentacles also appear, which usually range themselves in two series, those
belonging to the six endocceles being usually more prominent than the others.

The adults of Halcampa, Peachia, the Sagartidae, and the groups which receive
Actinia equina and Bunodes verrucosa, pass through this stage. The Halcampa,
described by Prof. R. Hertwig as H. clavus (1882), does not advance further.

6. A pair of small mesenteries, with their longitudinal muscles facing one
another, is developed in each exoccele.

This is the permanent condition of Halcampa chrysanthellum and H. arenarea,
except that the longitudinal muscles are undeveloped. In the adult of Peachia
hastata strong longitudinal muscles are developed on the new small mesenteries,
but only four pairs of mesenteries are formed. Those corresponding to the sulcular
exoccel (chamber b of diagram, PI. xxxvu., fig. 12) are absent. The other hexa-
merous Actiniae mentioned above pass beyond this stage.

Haddon — A Revision of the British Actimce.

353

7. These mesenteries grow larger, and other pairs appear successively in every
exoccele until a considerable number is formed.

Amongst the family Sagartidae the members of the sub-family Chondractininse
are characterized by the six primary pairs of mesenteries alone reaching the
oesophagus, the six pairs of the second cycle, those referred to in the preceding
paragraph (6), are imperfect, although mesenteries of the third, fourth, and even
of the fifth cycle may be present. In the sub-family Sargartinae, however, the
mesenteries of the second cycle and those of other cycles may, in a more or less
irregular manner, reach the oesophagus. In other Actiniae all the mesenteries may
be perfect.

As has been pointed out by other authors, we have the remarkable fact that
in the early development of the Actiniae the six-rayed arrangement of parts does
not occur, typical as it is of the adults, although it is not so universal as is
popularly imagined. As the late Prof. F. M. Balfour pointed out (1880, p. 140)
the number of mesenteric chambers increases in arithmetical progression up to a
certain stage ; thus we have for both mesenteries and their chambers the numbers
2, 4, 6, 8, 10, 12, but of these the numbers 2, 4, 8, 12, are of chief importance, and
alone appear to possess any phylogenetic significance.

I am not aware of any adult Hydroid-like organism which possesses a pair of
mesenterial ridges and two tentacles.

The relationship of the Hydra-tuba and Scyphostoma stages of the Scyphome-
dusae (Acalephae) to the Zoantharia is now generally admitted, indeed a group
(Taeniolatae) has been erected by Professor E. Haeckel to include them both.
Later Professor A. Gloette (1887) has similarly proposed the term Scyphozoa for
the same assemblage, but including the Ctenophora, as opposed to the remaining
Ccelenterata or Hydrozoa. The Scyphostoma have an oesophagus lined by ectoderm
(Stomodaeum), four glandular mesenteries, the edges of which are true craspeda,
and serve to digest food ; in their upper portion nematocysts are present. The
four tentacles are afterwards increased to eight, and finally to sixteen. It is
especially noteworthy that at first there are only two tentacles : probably this is
a reminiscence of a remote ancestor. The widespread occurrence of a symmetry
of four amongst the larvae of the Scyphozoa is very suggestive.

One is tempted to recall the tetrameral symmetry of the Rugose Corals
(Tetracoralla), as indicative of relationship to some primitive Scyphozoon, but for
the warning of Mr. J. J. Quelch (1886, p. 42), who says: — " Thus, as the result
of the foregoing considerations, there is not a single characteristic of the old group
Rugosa which will essentially separate its forms from the more typical Astraeids ;
and a direct expression is given to this fact by placing the families of the old
Rugosa (except the family Cyathaxonidae, which has been placed under the sub-
section Turbinolida) with the family Astraeidae, under the sub-section Astraeida."

TEANH. HOY. DUB. SOC, N.S. VOL. IV., PAET V. 3 E

354

Haddon — A Revision of the British Actinice.

A permanent octoradiate condition occurs in Edwardsia ; but it is difficult to
see where the Octocoralla (Alcyonaria) fit in; most probably they diverged much
earlier from the Scyphozoon stock.

The passage from an eight-rayed to a twelve-rayed symmetry has already
been fully described.

The following table illustrates the foregoing conclusions. It is designed to
illustrate various stages of development of certain Actiniae, but not to assert a
phylogeny.

The time has not yet arrived when we can construct a classification of the
Actinias as a whole.

Stages of
development
in terms of
mesenteries.

12 + 12
24, &c.

12 + 12

12

+ 4

Table of lines of development of certain Actiniae.

Typical hexameral Actinias

Halcampa
Peachia (young)

Halcampa (young)

Gonactinia [young) (young)

Edwardsia (young) (young) (young)

Scypkostoma larva, (young) (young) (young) (young)

(young)

(young) (young) (young) (young)

-Zoantliese.

-Ceriantheas ?

Above the black line new mesenteries arise in pairs within each exoccele, or
radially.

Below the line the mesenteries appear bilaterally with respect to the long axis
of the oesophagus.

The order of development of the mesenteries, later than those of their respec-
tive fundamental forms in both the Cerianthese and the Zoanthese is also bilateral.

Haddon — A Revision of the British Actinice.

355

BIBLIOGRAPHY.

1766. Pennant:

A British Zoology : London.

1767. C. LrNNE :

Sy sterna Naturae. Edit. xii.

1776. 0. F. Muller :

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1780. 0. Fabricius :

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1786. J. Ellis (the late) :

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1788-93. J. F. Gmelin :

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1806. 0. F. Muller :

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1815. L. Oken :

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1830. H. M. Blainville :

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1830. H. M. Blainville:

Manuel d'Actinologie et Zoophytologie.

1834. H. Ehrenberg :

Beitrage zur physiologischen Kenntniss der Korallenthiere im Allgemeinen und besonders des
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1835. J. F. Brandt :

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1835. M. Sars :

Beskrivelser og Jagttagelser over nogle moerkelige eller nye i Havet ved den Bergenske Kyst
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3 E 2

356

Haddon — A Revision of the British Actinias.

1842. A. DE QuATEEFAGES :

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Zool., ser. u., vol. xviii., p. 65.)

1846. J. D. Dana :

Report on Zoophytes, U. S. Explor. Exped., 1838-42, with Atlas.

1848. J. Dalyell :

Rare and remarkable Animals of Scotland.'

1851. W. P. Cocks:

Actiniae procured at Falmouth. (Nineteenth Ann. Rep. Roy. Cornwall Polytech. Soc,
pp. 3-11, pi. ii.)

1851. M. Saes:

Beretning om en i sommeren 1849 foretagen Zoologisk Reise i Lofoten og Finmarken. (Nyt.
Mag. Naturvid. vi., pp. 122-211.)

1853. P. H. Gosse :

On new or little-known Marine Animals [Actinia miniata, A. clavata, Ilyanthus mitchelii).
(Ann. Mag. Nat. Hist., ser. h., vol. xii.. pp. 125-128, p. 157; pi. x.)

1856. P. H. Gosse :

On Edwardsia camea, a new British Zoophyte. (Ann. Mag. Nat. Hist. ser. n., vol. xviii.,
p. 219 ; pi. ix., figs. 1-4.)

1857. H. Milne Edwaeds :

Histoire naturelle des Coralliaires ou Polypes proprement dits.

1858. P. H. Gosse :

On the British Actinia?. (Ann. Mag. Nat. Hist., ser. in., vol. i., p. 414.)
Characters and descriptions of some new British Sea-anemones. (Ann. Mag. Nat. Hist.,
ser. in., vol. ii., p. 192.)

1858. W. Thompson :

Remarks on the British Actinidae and re-arrangement of the genera. (Proc. Zool. Soc,
vol. xxvi., p. 145 ; also in Ann. Mag. Nat. Hist., ser. m., vol. ii., p. 229.)

1859. P. H. Gosse :

Characters and Descriptions of some British Sea Anemones. (Ann. Mag. Nat. Hist., ser. in.,
vol. iii., p. 47.)

1859. J. Koken :

Indberetning til Collegium academicum over en pa offentlige Bekostning foretagen Zoologisk
Reise i Sommeren, 1857. (Nyt. Mag. f. Naturvidensk, ix., p. 93.)

Haddon — A Revision of the British Actinice.

357

1860. P. H. Gosse :

Actinologia Britannica : A History of the British Sea Anemones and Corals : London.

[This work was originally published in parts, the parts appearing as follows on the first day of the
respective months : —

Part i.,

pp.

1-32,

March,

1858.

Part viii.,

pp.

225-256,

May,

1859.

., ii-,

pp.

33-64,

May,

J J

„ ix.,

pp.

257-288,

July,

„ Hi.,

pp.

65-96,

July,

5 J

pp.

289-320,

Sept.,

> >

pp.

97-128,

Sept.,

) >

,, xi.,

pp.

321-352,

Nov.,

v.,

pp.

129-160,

Nov.,

J »

Preface,

Dec,

j)

>, vi.,

pp.

161-192,

Jan.,

1859.

Part xii.,

pp.

353-362,

Jan.,

1860.

„ vii.,

pp.

193-224,

March,

)>

I have deemed it advisable to give the dates of publication of these parts, as it will clear up some
otherwise inexplicable facts of contemporary literature ; for example, species apparently described by
Mr. Gosse in 1860 are alluded to by authors in 1858. I gather from Mr. Gosse that only the first four
parts were dated. As the date was only on the temporary cover, and not in the letterpress, all the
species described in this work must date from 1860, the date on the title-page of the book when
complete.]

1860. C. . Lutken :

Nogle Bemarkinger om de ved de danske Kyster iagttagne Arter af Aktiniernes Gruppe.
(Vidensk. Meddel. Naturhist. Foren. Kjobenhavn., p. 184.)

1861. T. Hincks :

Catalogue of the Zoophytes of South Devon and South Cornwall. (Ann. Mag. Nat. Hist,
ser. in., vol. viii., pp. 152, 251, 290, 360.)

1864. A. E. Verrill :

Revision of the Polypi of Eastern Coast of the United States. (Mem. Soc. Nat. Hist.
Boston, vol. i. Read 1862, published 1864.)

1865. W. C. M'Intosh :

Note on two new species of Edwardsia. (Proc. Roy. Soc. Edinb., vol. v., p. 394; also in
Marine Intertebrate Fauna of St. Andrews (1875), pp. 37, 38 ; pi. ii., figs. 1-7.)

1868. A. M. Norman :

Shetland Final Dredging Report, pt. ii. (Rep. Brit. Assoc., 1868, pp. 232-345.)

1869. A. E. Verrill :

Notes on Radiata. No. 6. Review of the Corals and Polyps of the West Coast of America.
(Trans. Connect. Acad., vol. i., 1867-1871.)

1872. G. J. Allman :

On the Structure of Edwardsia. (Quart. Journ. Micr. Sci., vol. xii., p. 394 ; also in Rep. Brit.
Assoc., vol. xlii. (1872), p. 132.)

1872. H. de Lacaze-Duthiers :

Developpement des Coralliaires : Actiniaires sans Polypier. (Arch. Zool. Exper. et gener.
torn, i.)

1873. K. Mobius :

Jahresb. d. Commission z. wiss. Untersuch. d. Deutschen Meere in Kiel. 1871. (Abstract in
Ann. Mag. Nat. Hist., ser. iv., vol. xiii., 1874, p. 203.)

358 Haddon — A Revision of the British Actinice.

1873. A. E. Verrill :

Brief Contributions to Zoology : Dredging on the Coast of New England. (Amer. Jour. Sci.
ser. in., vol. v., p. 1., and vol. vi., p. 440.)

1874. S. F. Smith and O'Haeger :

Report on the Dredgings in the region of St. George's Bank in 1872. (Trans. Connect. Acad.,
vol. hi.)

1874. A. E. Veerill:

Brief contribution to Zoology from the Museum of Yale College, No. 28. Results of recent
dredging expeditions on the coast of New England, No. 6. (American Journal of Science,
ser. nr., vol. vii., pp. 405, 498 ; pi. vii., fig. 7.)

1875. P. Fischeb:

Recherches sur les Actinies des cotes oc^aniques de France. (Nouvelles Archives du Museum
d'Hist. Nat. de Paris ; torn, x., p. 193.)

1875. C. Lutken :

Arctic Manual and Instructions, p. 186.

1875. F. E. Schulze :

Jahresb. Com. Untersuch. Deutschen Meere in Kiel. Exped., 1872.

1876. A. M. Norman :

Report " Valorous " Expedition. (Proc. Roy. Soc, vol. xxv., No. 173, p. 202.)

1877. A. Andees :

On a New Genus and Species of Zoanthina Malacodermata (Panceria spongiosa, sp. n.).
(Quart. Journ. Micr. Sci. (N. S.), vol. xvii., p. 221, pi. xvi.)

1878. T. Studee.

Zweite Abtheilung der Anthozoa polyactinia welche wahrend der Reise S. M. S. Corvette
Gazelle um die Erde gesammelt werden. (Monatsber, Konigl. preuss. Akad. der Wissensch.
Berlin., pp. 524-550, pis. i.-v.)

1878. G. Von Koch :

Mittheilungen uber Coelenteraten Gephyra dohmii. (Morph. Jahrb., iv., pp. 74-87.)

1879. 0. and R. Heetwig :

Die Actinien anatomisch und histologisch mit besonderer Benicksichtigung des Nerven-
Muskelsystems untersucht : Jena.

1880. F. M. Balfour :

A Treatise on Comparative Embryology : London.

1880. G. von Koch :

Notizen iiber Korallen. (Morph. Jahrb. vi., p. 355, torn. 16.)

1880 a. A. Andres :

Intorno all' Edwardsia claparedii (Halcampa claparedii, Pane). (Atti R.Accad. Lincei, Roma,
3\ V. ; also in Mittheil. Zoolog. Stat. Neapel., n., p. 123.)

1880 b. A. Andees :

Prodromus neapolitanae actiniarum faunae addito generalis actiniarum bibliographise catalogo.
(Mittheil. Zoolog. Stat. Neapel., n., p. 305.)

Haddon — A Revision of the British Actinice. 359

1882. E. Hertwig :

Eeport on the Actiniaria. (Eeport on the Scientific Eesults of the Voyage of H. M. S.
" Challenger" during the years, 1873-76. Zoology, vol. vi., part 15.)

1882. A. F. Marion :

Actiniaires atlantiques des dragages de l'aviso le Travailleur. (Comptes rendus, xciv, p. 488 ;
translated in Ann. Mag. Nat. Hist., ser. v., vol. ix., 1882, p. 406.)

1882. A. E. Verrill :

Notice of the remarkable Marine Fauna occupying the outer banks of the Southern Coasts of
New England. No. 8. (Contributions to Zoology, Yale College, No. 49 ; Amer. Jour.
Sci., ser. in., vol. xxxiii., p. 135.)

1883. S. J. Hickson :

On the ciliated Groove (Siphonoglyphe) in the Stomatodaeum of the Alcyonarians. (Phil.
Trans., p. 693, pis. L, li.)

1883. A. Milnes Marshall :

Eeport on the Pennatulids dredged by H.M.S. " Triton." (Trans. Eoy. Soc, Edinb., vol.
xxxii., p. 125.)

1883. G. Muller :

Zur morphologie der scheidewande bei einigen Palythoa und Zoanthus. Marburg. (Disserta-
tion for Doctor's degree, privately printed.)

1883. A. E. Verrill :

Bull. Mus. Comp. Zool. xi., pp. 45-62, pis. v.-viii.

1884. A. Andres :

Le Attinie. Fauna u. Flora d. Golfes v. Neapel, ix., Leipzig. As a matter of fact this
monograph was published, in 1883, in the Atti E. Acad, dei Lincei, Eome (3 A), xiv. I
have quoted from the separately published edition, as it is probably the one which will be
in most general use. The pagination of the Eoman Academy's Transactions is of course
different.

1884. J. V. Carus :

Prodromus Faunse Mediterraneas.

1884. M. Faurot :

Sur l'anatomie de la Peachia hastata. (Comptes rendus xcviii., p. 756 ; translated in Ann.
Mag. Nat. Hist., ser. v., vol. viii., p. 417.)

1884. E. L. Mark:

Selections from Embryological Monographs, hi., Polyps. (Mem. Mus. Comp. Zool.,ix., No. 3,
Harvard Coll. Cambridge, Mass.)

1884. A. Sedgwick :

On the origin of Metameric Segmentation and some other Morphological Questions. (Quart.
Journ. Micr. Sci. (N. S.) xxiv., p. 43.)

1885. A. Erdmann :

Ueber einige neue Zoantheen. Ein Beitrag zur anatomischen und systematischen Kenntniss
der Actinien. (Jenaische Zeitschr. Naturwiss. xix., p. 430.)

360 Haddon — A Revision of the British Actiniae.

1885. G. H. Fowler :

The anatomy of the Madreporaria, I. (Quart. Journ. Micr. Sci. (N. S.), vol. xxv., p. 577,
pis. xl.-xlii.)

1885. A. C. Haddon and G. Y. Dixon :

The structure and habits of Peachia hastata (Gosse). (Proc. Roy. Dub. Soc. (N. S.), vol. iv.,
p. 399.)

1885. A. S. Pennington :

British Zoophytes.

1885. A. E. Verrill :

Results of the Explorations made by the steamer "Albatross" off the northern coast
of the United States. (Rep. U. S. Fish. Com. for 1883— Anthozoa, pp. 508-517 ;
Actiniaria, pp. 534, 535 ; pis. v.-viii., xliv.)

1886. G. Y. Dixon :

Notes on two Irish specimens of Echmrdsia tirnida (Quatrefages). (Proc. Roy. Dub. Soc.
(N.S.), vol. v., p. 100, pi. vi.)

1886. A. C. Haddon :

Preliminary Report on the Fauna of Dublin Bay. (Proc. Roy. Irish Acad., ser. n., vol. iv.,
Science, p. 523.)

Note on Salcampa ehrysanthellum, Peach. (Proc. Roy. Dub. Soc. (N.S.), vol. v., p. 1.)
First Report on the Marine Fauna of the south-west of Ireland. (Proc. Roy. Irish. Acad.,
ser. ii., vol. iv., Science, pp. 599-638.)

1886. J. J. Quelch :

Report on the Reef-Corals, collected by H. M. S. "Challenger." (" Challenger " Reports,
vol. xvi.)

1887. G. C. Bourne:

The Anatomy of the Madreporarian Coral, Fungia. Quart. Journ. Micr. Sci. (N. S.), vol. xxvii.,
p. 293, pis. xxiii.-xxv.)

1887. A. C. Haddon :

Note on arrangement of the Mesenteries in the parasitic larva of Halcampa ehrysanthellum
(Peach). (Proc. Roy. Dubl. Soc. (N. S.), vol. v., p. 473, pi. xi.)

1887. A. Goette :

Entwicklungsgeschichte der Aureiia aurita und Cotylorhiza tuberculoid, Hamburg. (Abhand.
zur Entwick. der Thiere., 4 Heft.)

1887. W. C. M'Intosh :

Notes from the St. Andrew's Marine Laboratory (under the Fishery Board of Scotland),
No. vii., No. 3, On the Commensalistic Habits of the larval forms of Peachia. (Ann.
Mag. Nat. Hist., ser. v., vol. xx., p. 101.)

1888. F. Blochjiann and C. Hilger :

Ueber Gonactiniu prolifera, Sars. Eine durch Quertheilung sich vermehrende Actinie. (Morph.
Jahrb. xiii., p. 385, pis. xiv., xv.)
1888. A. F. Dekon :

On the arrangement of the Mesenteries in the genus Sagartia, Gosse. (Proc. Roy. Dub. Soc.
(N. S., vol. vi., p. 136.)

Haddon — A Revision of the British Actinice. 361

1888. G. Y. Dixon :

Bemarks on Sagartia venusta and S. nivea. (Proc. Roy. Dub. Soc. (N. S.), vol. vi., p. 111.)
1888. A. C. Haddon :

On two species of Actinias from the Mergui Archipelago. (Journ. Linnean Soc. Zool., vol.
xxi., p. 247, pis. xix., xx.)

1888 a. A. C. Haddon :

Sixth Annual Report of the Fishery Board for Scotland, p. 281.

1888 b. A. C. Haddon :

Besearches at the St. Andrew's Marine Laboratory (under the Fishery Board for Scotland) —
On Larval Actinias parasitic on the Hydromedusae at St. Andrew's. (Ann. Mag. Nat. Hist.,
ser. vr., vol. ii., p. 256.)

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. V.

EXPLANATION OF PLATE XXXI.

TRANS. EOY. DUB. SOC, N.S. VOL. IV., PART V.

PLATE XXXI.

Chitonactis marioni, n. sp.

Side view of fully expanded animal on a spine of Dorocidaris papillata.
Side view of upper portion of the same during retraction.

Oephyra dohrnii, von Koch.

Group of cherry-coloured variety from locality near Great Skellig.
Groups of several specimens on tubes of Tuhdaria indivisa.
Side view of one of the same, and disc.

Actinauge richardi (Marion).

Group of three individuals, fully expanded ; above, disc of another specimen with

everted oesophagus ; natural size.

'/■/vjik/urtiM

EXPLANATION OF PLATE XXXII.

TRANS. ROY. DTJB. SOC, N.S. VOL. IV., PART V.

PLATE

XXXII.

Paraphellia expansa, g. and sp. nn.

Figure.

1. Fully expanded disc, x 4 diam.

2. Side view of individual, with pedal disc retracted, x about 3 diam.

3. Yiew of contracted specimen, with part of the arenaceous investment removed, x 2 diam.

4. View from above of fully expanded individual, divested of its covering of sand, x 2£ diam.

Halcampa arenarea, Haddon.

5. Side view of extended animal, about 3 diam ; also the same, greatly contracted ; and the disc

(diagrammatic), greatly enlarged.

" Sagartia," sp. (?)

6. Side view of fully extended animal attached to a Caryophyllia, x about li diam.

Chondr actinia digitata (Miiller).

7. Upper view of same, with the oesophagus puffed out.

8. Side view of a specimen drawn by Mr. P. H. Gosse, on June 11th, 1860, and presented to him by

Mi'. Stanger ; natural size.

9. Side view of a specimen collected and drawn by Mr. Joshua Alder, Newcastle, 1856 ; natural size.
10. Upper view of same, with the oesophagus puffed out.

EXPLANATION OF PLATE XXXIII.

TEANS. ROY. DUE. SOC, N.S. VOL. IV., PAET V.

PLATE XXXIII.

Hormathia margaritce, Gosse.

Figure.

1. Viewed from above, of preserved specimen, x 2 diam.

2. The same, from the side.

Oephyra dohrnii, von Koch.

3. (Cherry-coloured variety) (1886) portion of disk and tentacles, x 3 diam.

4. Side view of the same.

" Sagartia," sp. (?).

5. Preserved specimen on Caryophyllia ; natural size.

Paraphilia expansa, Haddon.

6. Preserved specimen (1886) ; natural size.

Chitonactis marioni, n. sp.

7. Upper view of preserved specimen.

8. Same specimen, viewed from above, when alive.

Actinauge richardi (Marion).

9. Side view of preserved specimen, natural size.

10. Several tentacles of the various ranks, from the living animal (drawn by Mr. T. H. Thomas).

Chondractinia digitata (Miiller).

1 1 . Side view of a contracted spirit specimen, x 2 diam.

12. Side view of an uncontracted spirit specimen, x 2 diam.

Chondractinia nodosa (Fabricius).

13. Side view of a preserved specimen ; natural size.

Malcampa arenarea, Haddon.

14. Preserved specimen (1886), x 2 diam.

JSdwardsia cornea, Gosse.

15. Preserved specimen, x 14 diam.

Edwardsia teeta, n. sp.

16. Preserved specimen, x 5 diam.

Edwardsia beautempsii, Quatrefages.

17. Living animal, contracted, x about 2 diam.

Trans. R. Dub. S..N.S., Vol. IV.

Plate XXX11I

ACHaddon del ad nat.

!•' I!ulh.'..iLhr Kdmr

EXPLANATION OF PLATE XXXIV.

THAN S . ROY. DUB. SOC, N.S. VOL. IV., PART. V.

PLATE XXXIV.

LETTERING ADOPTED IN ALL THE FIGURES.

a., . .

. acontia.

m.f., .

. mesenterial filament.

s. d.,

. sulcar directive mesentery.

ax. t., .

. axial tentacle.

n., . .

. nucleus.

s. 1. en.,

. sulco-lateral endoccele.

c. m.,

. circular muscle.

<BS., .

. oesophagus.

si., .

. suleulus.

c. m. en.,

. circular muscles of endo-

as. gr.,

. oesophageal groove.

si. d., .

. sulcular directive mesen-

derm.

ov., . .

. ovum.

tery. '

cu., . .

. cuticle.

p. d., .

. pedal disk.

si. en., .

. sulcular endoccele.

d., . .

. directive mesenteries.

p. in., .

. parietal muscle.

si. ex., .

. sulcular exoccele.

ec.f . .

. ectoderm.

r. m., .

. retractor muscle.

si. 1. en.,

. sulculo-lateral endoccele.

en., . .

. endoderm.

sc., . .

. sucker.

s. 1. m.,

. sulco-lateral mesentery.

g. .

. grains of sand.

s., . .

. sulcus.

si. 1. m.,

. sulculo-lateral mesentery.

1. ex., .

. lateral exoccele.

s. en., .

. sulcar endoccele.

sp., . .

. sperm-cell.

m., .

. mesogloea.

s. ex., .

. sulcar exoccele.

z.,

. zooxanthelte.

Paraphellia expansa, Haddon.

Figure.

1. Transverse section through middle of oesophageal region,

a * 10"

3

2. Transverse section through inferior portion of oesophageal region,

3. Vertical section of entire animal, x 4.

4. Transverse section of a portion of the body- wall

a * 1

3. Vertical section of entire animal, x 4.

2

2?'

Actinauge richardi (Marion).

5. Diagrammatic vertical section ; natural size.

g

6. Transverse section through oesophageal region, — .

(I ' o

2

7. Transverse section of secondary mesentery, — .

g

8. Section of a tubercle, •=.

IS

9. Longitudinal section of a portion of the sphincter muscle.

Trans. R.Dub.S.,N.S,Vol. IV.

Plate XXXIV.

[ 363 ]

VI.

ON THE FOSSIL FISH OF THE CKETACEOUS FOEMATIONS OF
SCANDINAVIA. By JAMES W. DAVIS, F.G.S., F.L.S., F.S.A., &c.

Plates XXXVIII to XLVI.
[Read April 16, 1890.]
[COMMUNICATED BY PROFESSOR E. P. WRIGHT, M.P.]

I. — INTRODUCTION.

During the year 1889 I had the pleasure, accompanied by my friend Mr. A. Smith
Woodward, to visit some of the principal Museums in Sweden and Denmark, and
to become personally known to those who were in charge of them. The
collection of fish-remains from the chalk of South Sweden have received little
attention since the time of S. Nillson, who first discovered fish remains in the
Swedish chalk, and who described a few teeth in his work on the " Petrificata
Suecana, formationis Cretaceae," published in 1827. Eleven years afterwards
W. Hissinger copied the plates of Nillson into his " Lethea Suecica seu Petrificata
Sueciae," but does not appear to have advanced beyond his predecessor. Since
that time the number of examples of fossil fishes has largely increased, and the
collections are now of great interest. The present memoir is due mainly to the
suggestion of Dr. Bernard Lundgren, that the enlarged collections needed, and
were worthy of, renewed study ; and his offer, coupled with a subsequent one by
Dr. G. Lindstrom, to allow the specimens to be sent to England for this purpose,
was a sufficient inducement to me to accept it. An application to Dr. C. Lutken
for the collection at Copenhagen was also readily granted, and others followed.

I have unfeigned pleasure in expressing my great indebtedness to Dr. G. Lind-
strom, Keeper of Palaeontology, National Museum, Stockholm ; to Dr. Bernard
Lundgren of the University of Lund ; to Professor 0. Torrell, Director of the Geo-
logical Survey of Sweden ; to Dr. C. Lutken, Professor of Zoology at the University
of Copenhagen ; to Dr. F. Johnstrup, Director of the University Mineralogical
and Geological Museum at Copenhagen, and to others, for their great courtesy
and kindness in unreservedly placing the collections in their charge at my
disposal, and so affording me the best opportunities possible to identify and
record the occurrence of the fish remains which have been found in the chalk of
Scandinavia. Dr. Lutken has kindly furnished me with particulars of his own

TEAKS. EOT. DTJB. SOC, N.S. VOL. IV. PAEX VI. 3 G

364 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

unpublished observations on the selachian teeth found in the white chalk of Faxe
and Saltholm. The opinions of an authority of so high eminence have been very
valuable. The collection from the University Zoological Museum at Copenhagen
contains many specimens from the original museum formed by the late King
Christian VIII. I am also indebted to Dr. Johnstrup for stratigraphical
information respecting the localities in Denmark. Dr. Bernard Lundgren has
furnished me with a table of formations, showing also the districts in which the
localities occur from which fish remains have been obtained ; and a published
list of the fossil fauna of Sweden. And to Dr. Lindstrom I am under obligation
for a variety of information not easily enumerated.

Dr. Henry Woodward, keeper of the geological collections at the British
Museum, has, with his usual kindness, afforded me every opportunity to compare
and study the specimens under his charge with the Scandinavian ones ; and to
Mr. A. Smith Woodward I am indebted for suggestions and information bearing
on the subject of this memoir, and for the uniform courtesy and kindness with
which he has given me advice and assistance both in and out of the Museum.

The ichthyic fauna of the Swedish chalk offers several points of considerable
interest. It has shown, generally, a closer relationship to the cretaceous fauna of
the North of Europe, as represented in the English and French chalk, than to the
more highly specialized fauna of Asia Minor ; but it does not afford representatives
of several of the Physostomous Teleosteans such as Ichthyodectes, Protosphyrama,
and Pachyrhizodus, which occur in the English chalk, and have been found in the
Upper Cretaceous rocks of North America. A few teeth occur in the Swedish
chalk which are referred to Enchodus. Examples of a large species of Dercetis
occur, and some fragmentary remains which are probably Clupean. The highly
specialized forms, such as Cheirothrix, Rhinellus, Spaniodon, Eurygnathus, and
Eurypholis, found in the Lebanon chalk, do not occur in the chalk of Sweden.
Amongst the Acanthopterygian Teleosteans the most important are the remains of
Beryx and Hoplopteryx. These genera are represented in both the English and
Lebanon chalk.

The great majority of the fish remains are Selachian, and comprise no fewer
than twenty-four species. Three species, viz. Carcharodon rondeletii (M. & H.),
Otodus obliquus (Ag.), and Odontaspis acutissimus (Ag.), are usually regarded and
known as indicating a tertiary fauna ; but in the Scandinavian chalk they have
been found in association with many undoubted Cretaceous forms in the Faxe
limestone or chalk, and so appear to prove that these species were in existence
before the advent of the deposition of the Tertiary strata. The Tectospondylic
sharks* are represented by two species of Phychodus and indefinable teeth of

* C. Hasse, Das Naturliche System der Elasniobranchier, 1879-82.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 365

Myliobatis. The Asterospondylic sharks occur in very large numbers, and
represent several genera. Beautifully preserved specimens of Notidanus, Sca-
panorhynchus (Rhinognathus), Odontaspis, Oxyrhina, Otodus, Lamna, and Corax
are abundant, and have a wide vertical range. The teeth here described as
Oxyrhina lundgreni possess peculiarities which, in some respects, dissociate them
from Oxyrhina, and it may be found necessary to form them into a new genus.
The character and extent of the Selachian fauna indicates conditions very similar
to those accompanying the deposition of the English and French chalk and that
of Central Europe generally, whilst it affords comparatively little data for
comparison with that of Lebanon. The occurrence of numerous teeth of
Scapanorhynchus in the Swedish area is worthy of note, but the fish are not found
preserved bodily as they are in the Lebanon chalk.

The classification adopted is based, as far as possible, on that of the recently-
published " Catalogue of the Fossil Fishes in the British Museum (Natural
History), Part I.," by Mr. A. Smith Woodward. Whilst recognising the great
merits of this work, and the painstaking care with which it has been compiled
and arranged, it cannot be denied that there are some portions of the re-arranged
classification which are open to doubt ; and, possibly, to no group of fossil fishes
does this apply more forcibly than to the Lamnidse. I propose, therefore, to
briefly review the most salient characteristics of the genera composing the
Lamnidse, especially those found in the chalk of Scandinavia, and drawing such
deductions therefrom as appear to me most reasonable.

The following genera are included in the family Lamnidse : —

Sphenodus, Agass. (Orthacodus, Smith Woodw.).
Alopecias, M. and H.

Cetorhinus, de Blainv. (Selache, Cuv., Hasse).

Carcharodon, M. and H.

Corax, Agass.

Otodus, Agass.

Oxyrhina, Agass.

Lamna, Cuvier.

Odontaspis, Agass.

Scapanorhynchus, Smith Woodw.

Sphenodus comprises four or five species, of which only the teeth are known,
characterised by a wide base, with a slender median crown. All the species are
found in the Jurassic rocks of the Continent, but have not been found in England.
The genus Alopecias is also restricted to the Continent, and is found in the
Molasse of Baltringen and the Eocene strata of Prussia. Selache or Cetorhinus,

3 G 2

366 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

founded on teeth and vertebrae which resemble those of Selache (Cetorhinus)
maxima, occurs in the Tertiary strata of Antwerp, Italy, and Germany. The
genus Carcharodon was established by Miiller and Henle, who separated the
species of this genus from those of Carcharias.* The type of the new genus was
Carcharodon rondeletii, Mull, and Henle. The latter authors still further distinguished
the two genera by the microscopical examination of their teeth. Those of the
genus Carcharias were found to be hollow, whilst those of Carcharodon were solid,
like those of the genera constituting the Lamnidae. The Carcharodon was
therefore removed, and incorporated with the family of Lamnidse. The type of
the genus is the single existing species C. rondeletii. The teeth of this species
attain a length of an inch and a-half, and the entire length of the fish approaches
forty feet. The teeth of the Tertiary representative of the genus C. megalodon are
four or five inches in length ; and if the fish was proportionally large it must have
been of extraordinary size. The teeth of C. rondeletii exhibit considerable variety
of form, but are all triangular, with serrated margins, but without lateral cones or
denticles. The teeth in front on each side the symphysis of the jaws are higher
in the crown and narrower at the base than those located further back ; the posterior
teeth gradually diminish in size, and, at the same time, become very broad
in comparison to the height. The teeth of the lower jaw are more lance-like than
those of the upper one, which are more uniformly triangular, with straighter
margins.

The second dorsal fin and the anal are small. The lower lobe of the caudal
fin is well developed, with a keel along the side, and there is a pit at its root.

Agassiz, in addition to the species of Carcharodon found fossil, which closely
resembled the existing one, included in the genus a number of others which
were unlike the type in possessing well-developed lateral denticles on their
anterior and posterior borders. Whilst recognising the irregularity in form, "J" it did
not appear of sufficient importance to justify the establishment of a new genus.
Other species, in addition to the lateral denticles, depart still further from the
type, in having the anterior border very much arched. Such species are
Carcharodon leptodon, C. disauris, C. megalotis, C. heterodon, C. auriculatus,%
C toliapicus,§ and others. Agassiz is more specific in the statement of his
opinion with respect to these species, that they ought, at some time, to be
isolated with others to form a genus apart. He is confirmed in this opinion by
the fact that in the living species the tendency of the teeth to assume an arched
form is scarcely perceptible, whilst it is constantly seen in some other genera of
Lamnidse, and in true examples of Carcharias.

* Syst. beschrieb. Plagiostom, p. 70. 1841.
•J- Rech. Poiss. Foss., vol. iii., p. 246.

J Agassiz, Poiss. Foss., vol. vii., pi. xxviii.
§ Op. cit., pi. xxx. a, fig. 14.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 367

Corax is known only by the teeth. They are sufficiently distinctive in form
and of world-wide distribution. They are distinguished from the teeth of the
existing Carcharias and Galeus, to which they bear considerable resemblance, by
having no central cavity. The teeth of the existing fishes are hollow.

Teeth of Otodus are only known in a fossil state. The genus was instituted
by Agassiz for teeth which exhibited forms intermediate between Carcharodon on
the one side, and Oxyrhina and Lamna on the other. They agree with the
genus Lamna in possessing lateral denticles ; but whilst those of Lamna and
Odontaspis are cylindrical and sharply pointed, those of Otodus are larger, flat,
and blunt. The same characters may also be said to distinguish the crown of
each respectively. The root of Otodus is very large and thick; but it has not the
extended horn -like projections which characterize Lamna.* From Oxyrhina this
genus is distinguished by the presence of the lateral denticles, and from Carcha-
rodon it is separated by the absence of the serrated margins which characterize
the former. Agassiz regards this character as of great importance, and though it
may be of doubtful value in some species placed on the confines of the genera, he
regards it as not less decisive in the greater number. He says, however (p. 266) :
"II en est de ceci comme de toutes nos diagnoses ; elles ne sont vraies que dans
certaines limites, et c'est a la perspicacity du naturaliste a reconnaitre et a sentir
oil ces limites se trouvent." The microscopical structure of the teeth is solid and
massive, as in Carcharodon and the true Lamna. The genus appears first in the
Cretaceous rocks, was abundant in the Tertiaries, and died out before the existing
period.

The genus Oxyrhina includes one or two existing species. The type of the
genus, and the one best known, is Oxyrhina spattanzani {Lamna oxyrhina, Cuv.
and Val.). The teeth are completely free from lateral denticles, and the margins
are smooth. The crown of the tooth is very similar in form to that of Otodus;
and imperfectly-preserved specimens of Otodus, from which the base has been
broken so as to detach the lateral denticles, can with difficulty be distinguished
from Oxyrhina. The fossil teeth attain a considerable size ; they conform
generally with the ordinary arrangement of the teeth in sharks ; those situated
on the anterior part of the jaws are more lanceolate and acutely pointed than
those occupying a median position, whilst the posterior teeth are smaller,
triangular, and much compressed.

The genus Lamna was originally founded by Cuvier,t and embraced a variety
of fishes which have since been taken as the types of other genera, amongst them
Otodus, Carcharodon, and Oxyrhina, characterized by the form of the teeth. Of
the existing sharks, Lamna cornubica, Cuv., may be taken as the type of the genus.

* Agass. Poiss. Foss., vol. iii., p. 266.

f Eegne Animal, vol. ii., p. 126. 1827.

368 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Miiller and Henle, amongst other characters of the genus, give:* "the second
dorsal and anal small of equal dimensions, opposite ; pit at base of caudal distinct,
a keel along each side of the tail." These characters apply equally to Oxyrhina
and Carcharodon ; Odontaspis is distinguished by the second dorsal and anal fins
being large ; having no pit at the root of the tail, and the absence of keels along
the lateral surface. In all three genera the branchial arches are large and situated
in front of the pectoral fin. All the characters on which Miiller and Henle
based their classification are external, and pertaining to parts of the body which
are not usually found in a fossil state, and the palaeontologist, as Agassiz points
out,t sees with regret that no account whatever is taken of the skeleton or the
dentition ; and it is a remarkable coincidence, that the teeth which present the
nearest resemblance, viz. those of Lamna and Odontaspis, should be distinctly
removed by the external form of the caudal fin, and by the position and size of the
dorsal and anal fins to separate genera; whilst Cetorhinus, Blain. (Selache, Cuv.),
Oxyrhina, Agass., and Carcharodon, Miiller and Henle, which have teeth of
such great dissimilarity to Lamna, are grouped in the same family in close re-
lationship with that genus.

The teeth of Lamna comubica, Cuv., are more or less varied inform indifferent
parts of the jaws ; they may be described as possessing a high, median, cone-
shaped crown, flat, and compressed antero-posteriorly, with smooth margins ; a
single lateral denticle exists on each side of the median cone. The median cone
approaches to that of Otodus in form on the one side, but the lateral cones are
smaller and more acuminate ; and on the other, it possesses much resemblance to
some of the teeth of Odontaspis. It is principally distinguished by the cylindrical,
and often twisted form of Odontaspis, which has also longer and more pointed
lateral denticles. In Lamna the lateral denticles do not number more than one
on each side, but in Odontaspis there are frequently two, and occasionally three
on each side. The number is, however, inconstant, and even the teeth of the
same fish sometimes are variable. Agassiz very forcibly remarks that the variation
observed in the number of the lateral denticles is not calculated to inspire a great
amount of confidence in their value for determining genera.

The teeth of Lamna are readily distinguished from those of Oxyrhina, if the
base of the tooth and the root are well preserved, because Oxyrhina has no lateral
denticles ; from those of Otodus they are less readily distinguished, and some
intermediate species appear to bridge over the limits between the two genera,
such for example as Otodus append icidatus, one of the most common forms, which
can scarcely be distinguished from some of the Lamna.

Some of the characters of Odontaspis have already been enumerated. The

* Systematische Beschreibung der Plagiostomen, p. 66. f Poiss. Foss., vol. iii., p. 287.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 369

genus is represented by species still existing. In one of them, Odontaspis ferox,
Agass., all the teeth except those situated most posteriorly, have a high, narrow,
pointed crown, on each side of which are two, sometimes three, rounded and
acuminate denticles. Both these and the median cone are more or less cylindrical,
and usually exhibit a sygmoidal curvature. The teeth of both the upper and
lower jaw are similar in form ; on each side of the symphysis there is a small
pointed tooth, succeeded by much larger ones, narrow at the base as compared
with the height of the crown. In the upper jaw between the second and third
large tooth, the fourth and succeeding ones from the symphysis, there are four
teeth, very small, about one-third the height of the large front teeth. After these
are larger ones, broader at the base, all with acuminate crowns, and diminishing
in size backwards. In the lower jaw the intermediate small teeth do not occur,
but the teeth gradually diminish in height and size backwards. All are possessed
of two lateral denticles on each margin of the teeth. Agassiz* did not consider
that the teeth of Odontaspis were separated with sufficient distinctness from
Lamna to warrant him in forming a new genus ; but the teeth found fossil which
approached the living Odontaspis, he indicated by placing the word in a parenthesis.

Another genus of the Lamnidse occurs in the chalk of Mount Lebanon, and
was described by the writerf as Rhinognathus. It forms one of a very few
instances in which the body of a Lamnoid fish with teeth in the natural position
have been found fossil. It is distinguished from existing genera by the length of
the anal fin. The body is long, and the snout much elongated, and more or less
spatulate. The teeth are long and accuminate, with a pair of small lateral
denticles in the anterior part of the jaws, broader and shorter behind. The
teeth are not readily distinguishable from those of Odontaspis ; and the broader
ones are not unlike some of the species of Lamna. Mr. A. Smith Woodward^ has
pointed out that the generic name Rhinognathus was pre-occupied by Fairmaire
in 1873, and has suggested Scapanorhynchus in its stead. §

In addition to the species from Lebanon, Mr. Woodward has included under
this genus several species described by authors as Lamna and Odontaspis.

Dr. H. E. Sauvage|| in 1872 described a number of fish remains from the
Cretaceous rocks of Sarthe, and amongst others, species of the genera Oxyrhina,
Otodus, Lamna, and Odontaspis. Agreeing with Agassiz in the diagnosis of
* Poiss. Foss., vol. iii., p. 288.

f James "W. Davis On the Fossil Fishes of the Chalk of Mt. Lebanon, in Trans. Roy. Dub. Soc, N.S.,
1887, part v., toI. iii., p. 480.

X Catalogue Foss. Fishes in the Brit. Mus., 1889, part i., p. 351.

§ The inference drawn by Mr. "Woodward that this genus was considered as one of the Spinacidse is
incorrect. The omission of a line after the description of the preceding species may have led to the error.

|| Rech. sur les Poiss. Foss. du Terrain Cretace de la Sarthe, in Bibl. Ecole Hautes Etudes, vol. v., art.
9, p. 20.

370 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Oxyrhina, he observes that in the young stages of Lamna the teeth are without
lateral denticles, and that these only develope later. Of the genus Otodus, he
remarks that it is closely allied with Lamna, from which it only differs in the
greater development of the lateral denticles, their broader and less slender form.
The teeth of Otodus, whilst having the form of those of Carcharodon, are not
serrated on the margins, but in the opinion of M. Sauvage the three genera
named are closely related. He quotes an observation of M. Pictet, that these
teeth in many instances vary more from different parts of the same mouth than
their homologues in another species, and that this variation renders the difficulty
of the interpretation of their exact specific characters very great. This observa-
tion applies with considerable force to the genera Lamna and Odontaspis, the
teeth of which closely resemble each other ; but the fishes still existing enable the
naturalist to study and compare them, and their relationship is far more distant
than some of the other genera whose teeth have less resemblance. Palseonto-
logically it is very difficult to separate the two genera, which are quite distinct in
living examples.

In the year 1854 Valerian Kiprijanoff described a number of Selachian teeth
from the Cenomanian ferruginous sandstones of the governments of Kursk and
Orel, in Russia.* The characteristics of the teeth of the genera before named,
as defined by Agassiz, are cited ; [the difficulty of determining fragmentary
examples is stated to be almost insurmountable, and the microscopical examination
of the structure of the crown of Otodus, Lamna, and Oxyrhina is found to afford
no definite characteristics. The description of several species of Otodus, led the
author to seek the relationship of the genus with other associated forms, and he
expressed the opinion founded on his investigation, that the broad teeth approach
most nearly to Carcharodon, whilst towards the opposite extreme their similarity
to the teeth of Lamna stand out clearly. Specimens without lateral denticles are
indistinguishable from the teeth of Oxyrhina. Kiprijanoff states that in young
examples the teeth of Odontaspis possess lateral denticles at an earlier stage than
do those of Lamna ; and he regrets that an example of the jaw of Otodus has not
been found, so that some information as to the arrangement of the teeth in situ
might be obtained.

Professor Zittelf accepts the general definition of the genera of the Lamnidse,
and cites the opinion of C. Hasse % that the Lamnidae have developed from the
Scylliolamnidse, with which they are nearly connected, especially through the

* Fiscb-TJeberreste im Kurskscben eisenbaltigen Sandsteine by Valerian Kiprijanoff ; Bull, de la Soc.
Imperiale des JSaturalistes de Moscou, 1854, vol. xxvii., p. 373.

f Handbucb der Palaeontologie von Karl A. Zittel, band iii., p. 81. 1887.

\ Das Natiirliche system der Elasmobrancbier von C. Hasse ; 1879 : see Stammtafel i.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 371

genus Otodus ; at the same time, regarding Otodus as a connecting link between
the two families, he considers that it is so close to the typical Lamnidas that it is
difficult to draw a line to divide them.

Perhaps the most recent contribution to the subject is by A. Smith Woodward
in the Catalogue of the Fossil Fishes in the British Museum.* The great bulk of
the teeth of Lamna, previously described, are transferred to the genus Odontaspis,
and those of Otodus to the genus Lamna; Otodus, except as a synonym,
dropping out of the vocabulary. The Lebanon genus Rhinognathus renamed
Scaphanorhynchus is accepted, and included with it are some of the species of
Lamna (Odontaspis) described by Agassiz. Oxyrhina is retained without alteration,
and the teeth are defined as without denticles, but it is stated on another page that
some of the teeth of this genus have minute denticles. Woodward is of opinion
that " although only differing from Lamna in the prevailing absence of lateral
denticles in the teeth, it is convenient from a palaeontological point of view to
retain Oxyrhina as a distinct genus, more especially as several forms of these
teeth bear specific names identical with those referable to Lamna proper." Lamna
acuminata, Agassiz f, is included as a synonym of Oxyrhina mantelli, Agass.,
apparently on the authority of Sauvage, but that author % is doubtful whether the
teeth, figs. 55, 56, 57, are referable to L. acuminata, but has no doubt about fig.
54, which he accepts as the type of the species. If this view be correct, the tooth
represented by fig. 54, Woodward, to be consistent, should have included in his
genus Odontaspis ; the presence of well-formed lateral denticles clearly indicates
that genus. Carcharodon remains unchanged as a genus, but the species are re-
distributed.

Sauvage § in the memoir already cited, points out that M. Reuss || has given a
figure of a tooth with feeble denticles, which that author considered to be an
example of Oxyrhina mantelli, Ag. Sauvage, however, gives reasons for believing
that the determination of Reuss is erroneous, and that the tooth ought be
classed with Otodus oxyrhinoides, Sauvage. It is probable that an equally
careful examination of other examples of teeth which possess evidence of lateral
denticles, would prove that they ought not to be considered as pertaining to
Oxyrhina, although they may have been found associated with undoubted teeth of
that genus, and described with them.

Having thus briefly indicated the genera included in the family of the Lamnidse,
it is proposed to sum up the evidence, and if possible arrive at some reasonable
view for the classification of a group of fish-remains which are perhaps as per-

* Part i., p. 349, et seq.

f Poiss. Foss., vol. iii., p. 292, pi. xxxra.tf, fig. 54 (? non figs. 55, 57).
X Poiss. Foss. de la Sarthe, p. 35. § Op. cit., p. 25.

|| Verst. der Bohm. Kreid., 1845, pi. in., fig. 6.

TRANS. EOT. DUB. SOC, N.S., VOL. IV., PAJB.I. VI. 3 H

372 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

plexing as any in the whole range of palaeontological science. The most
profitable method of investigating fossil remains is by comparison with existing
forms, and it is fortunate that all the genera are not yet extinct ; and though the
fossil forms far outnumber the existing ones, there are still examples of Carcharo-
don, Lamna, Oxyrhina, and Odontaspis. As already observed the characters of
the first three existing genera as defined by Miiller and Henle, having reference
to the size, form, and position of the fins and tail, are identical, and so far as
those tests are concerned do not indicate any generic differences. Odontaspis, on
the other hand, differs from those named, in the form and position of the fins and
tail, to such an extent as to induce Sauvage to place it as a separate family ;
whilst, judging from the teeth alone, Agassiz and others have regarded them as
at most a sub -genus of Lamna. After carefully considering the divisions of the
Lamnidae attempted by Miiller and Henle, Agassiz expresses the opinion that
they may be tangible enough, and very serviceable in existing forms, when the
whole of the structure of the fish may be studied, but of little use when consider-
ing and attempting to decipher a mass of detached fragments, in nearly all cases
consisting of isolated teeth or vertebrae.

The Cretaceous fish-remains, Agassiz says, are characterized by a large
number of new types which have not existed at an earlier period. The group of
teeth with crenulated margins appears for the first time ; and amongst the smooth
teeth are several types equally new, such as Otodus, Oxyrhina, and the subulate
Lamna, or Odontaspis. The greatest difficulty consists in distinguishing between
Otodus and Oxyrhina ; and between Otodus and certain forms of Lamna ; also, it
is necessary in certain cases to renounce the hope of rigorously determining
fragments of teeth deprived of their roots. The difficulties which encompassed
Agassiz have increased since he wrote; and the discovery of numerous forms in all
parts of the world, and the accumulation of large collections of fish-remains in
public and private museums, have only served to produce a still more complicated
result and render still more difficult a satisfactory system of classification.

The existing Lamnidae as represented in Carcharodon and Oxyrhina indicate
two distinct forms of dentition both free from lateral denticles, the former with
serrated anterior and posterior margins, and the latter with those margins devoid
of serrations. These are abundant in the Tertiary strata, and Oxyrhina also in
the Cretaceous.

Agassiz held the opinion that the serrated margin of the teeth was of generic
importance, and this led him to include a number of forms with, well-developed
lateral denticles in the genus Carcharodon because they had serrated margins.
The question immediately arises whether the serrated margin, or the presence of
secondary cones is of greater generic importance. So far as the evidence of the
existing species goes, there is no trace of lateral cones or denticles, and if

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 373

C. rondeletii be taken as the type, then it becomes anomalous to include in the
genus such forms as Carcharodon heterodon, Ag., C. megalotis, Ag., C. auriculatus,
Ag., C. angustidens, Ag., and others. In form and size they approach very nearly
to some of the larger species of Otodus, such as 0. obliquus, Ag., and if the margins
of the latter were serrated would be indistinguishable from it.

Noetling has already suggested that Otodus should be joined to Carcharodon ;
but it appears much more reasonable, either that the forms associated with
Carcharodon which possess lateral denticles should be considered as species of
Otodus, or regarded as a separate genus.

Having regard to the remaining genera Lamna, Otodus, and Odontaspis,
existing species of the first and last still survive ; but unfortunately, hitherto, no
specimen of a living Otodus has been discovered, but so many wonderful types
have been found by deep sea dredging and more careful search, during the past
few years, that it may not be impossible that still others may be brought to light.
At any rate, until more reliable information is accessible, it may best serve the
purpose of the palaeontologist to regard the dismembered fragments simply as
"forms" exhibiting certain tendencies of a more or less definite character.
Sufficient has already been advanced to show that any lines of absolute demarca-
tion into genera, it might almost be said species, is impossible ; and the researches
of every fresh student may lead to new opinions formulated in new varieties of
nomenclature. Already the subject is almost hopelessly confounded ; the trans-
position of species is bewildering ; and after all there is no firm basis on which to
build up a natural classification.

One of the principal difficulties appears to be, that it should be desired to make
an extremely large series of fossils, representing an enormous development of the
Selachians, fit to a minimized series of living representatives which are
rapidly dying out; and that sufficient credit is not given to the variety and
number of the species which obtained during the ascendancy of the family.
Accepting this view it may be advisable to regard the teeth, as already suggested,
as "forms" representing members of the family, and classify them accordingly;
and it scarcely seems necessary to suggest that the successive redistribution of
species amongst existing, or newly devised genera, is to be deprecated. The
genera as defined by Agassiz embrace already a wide range of species, and have,
hitherto, proved adequate. They are universally known and accepted, and have
tolerably well-defined limits. Taking as types, Otodus obliquus, and the existing
species Lamna cornubica, and Odontaspis ferox, the palaeontologist will be able to
group the ever-varying fossil forms around these centres, and though they may
possess characters expressing relationship with more than one species, succeeding
discoveries may show that these only express the connecting links of an unbroken
line of evolutional development.

3 H 2

374 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

II. — CLASSIFIED DESCRIPTION OF THE FOSSIL FISH.

Class. — PISCES.
Sub-Class. — ELASMOBRANCHIL

Order. — Selachii .

Sub-Order. — Tectospondyli.

Family. — MYLIOBA TIDiE.

Genus. Myliobatis. Cuvier. " Regne Animal," vol. ii., p. 137. 1817.

Head free from the disk ; so-called cephalic fin single. Teeth large, flat,
hexangular, tesselated, arranged in seven antero-posterior series. The dentition
of the upper jaw strongly arched antero-posteriorly, that of the lower jaw quite
flat. Dental crown smooth, or slightly striated ; attached surface of root
longitudinally rigid and grooved. Except in very young individuals, in which
the teeth are all approximately of equal size, the median row is relatively very
broad, while the teeth of the three lateral series on each side are rarely broader
than long. Tail with a dorsal fin near its root, generally with a posteriorly-
situated barbed spine.

Myliobatis, sp. ?

Fragments of the teeth of this genus occur in the collection of the University
of Lund. The coronal surface is smooth, and presents a somewhat reticulated
appearance, due to the attrition of the upper extremities of the descending
nutritive canals. The root, composed of coarse lamellae, is smaller than the
crown, and is separated from it by a concave depression of the posterior surface,
the root projecting beyond the crown ; on the anterior surface the reverse happens,
the surface of the crown extending beyond the root.

The specimens are fragmentary, and of too indefinite a character to determine
the species.

Ex coll. — Geological collection, University of Lund.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 375

Genus. Ptychodus. Agassiz. " Poiss. Foss.," vol. iii., p. 150. 1839.
Syn.— Aulodus, F. Dixon, " Foss. Sussex.," p. 366. 1850.

Teeth quadrate in form, with elevated crown, somewhat overhanging-, and
sharply separated from the root by a constriction. The crown is enamelled,
and ornamented with large transverse or radiating ridges, surrounded by a more
finely-marked marginal area of greater or less extent. The surface of attachment
of root is smooth. In one jaw, presumably the lower, the median series of teeth
is the largest, and the lateral rows are arranged symmetrically, diminishing in
size to the left and right. In the opposing dentition the median series is very
small, and the first lateral row on each side large, with the outer lateral series
successively diminishing in size. The vertebrae are very deep compared with
their length, complete, and apparently cyclospondylic in structure.

The well-known teeth of Ptychodus were supposed by Mantell * to have formed
the dental armature of a teleostean fish nearly allied with the Diodon. The
observations of Agassiz, t and the microscopical investigations of Owen, % led to
the conclusion that the arrangement of the teeth of Ptychodus closely resembled
that of the Cestraciont sharks. The absence of any specimens showing the teeth
in actual position has led to a general acceptance of the view enunciated by
Agassiz. More recently, Cope,§ in America, and Smith Woodward, || in this
country, have been able, by the discovery of more perfect specimens, to arrive at
conclusions of great importance. Cope demonstrated that the spinous processes
supposed to have been the dorsal spines of Ptychodus were the fin-rays of a
Teleostean fish ; and Woodward has shown that the teeth have no agreement with
the dental arrangement in the Cestraciont shark, but that the dentition is that of a
true ray. The arrangement of the teeth is in parallel rows, crossing the rami at
right angles. There is a median row in each jaw, and on either side of it there
are series placed symmetrically right and left. In the upper jaw the median teeth
are small ; the largest are placed in the first lateral series, from which there is a
gradual diminution in size outwards. In the lower jaw the median teeth form

* Fossils of the South Downs, p. 231. 1822.

+ Recherehes sur les Poissons Fossiles, vol. iii., pp. 56-59, 150-158, 162.

% On the Structure of Teeth, Brit. Assoc. Eep., 1838, Trans. Sect., p. 140; and Odontography,
pp. 57-59, pis. xvrn., xix.

§ Vertehrata of the Cretaceous Formations of the "West (U. S. Geol. Surv. Terr., 1875),
p. 244 a.—f.

|| Quart. Journ. Geol. Soc, vol. xliii., pp. 123-130., pi. x.

376 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

the largest row, fitting into the central groove of the opposing dentition, and on
either side the teeth of the lateral series become successively smaller.*

Professor E. D. Cope f has discovered an interesting series of teeth in the
uppermost Cretaceous beds of Maria Farinha, which apparently occupies a position
intermediate between Ptychodus and the living ray, Myliobatis, and which he has
named Apocopodon. The teeth are covered with a thick layer of enamel, which
is ridged antero-posteriorly. The median teeth are shorter than Myliobatis, and
differ from both that genus and also Zygobatis in being exactly parallelogrammic
in outline, the extremities being truncated instead of angulated, as in those
genera. It may also be noted, that some of the Eocene Myliobatidae possess
teeth which approach more or less closely to the form of Ptychodus. A species
described by Leidy % from the phosphate beds of North Carolina as Myliobatis
juyosus, may be taken as an illustration. Professor W. Dames § has also described
detached teeth from the Tuffkreide of Maastricht which appear to possess
characteristics indicating an intermediate position between Ptychodus and
Myliobatis, and so forming a sort of connecting link. The teeth are named by
Dames Rhombodus binkhorsti. The occurrence of these intermediate forms in
various and widely separated parts of the world may indicate that the Ptychodonts
were the antecedent types of the Myliobatidae; and they certainly assist in
confirming the results of Smith Woodward's researches.

Ptychodus decurrens, Agassiz.

(PI. xxxviii., figs. 1, 2.)

Dens piscis ostracionis. Bruckmann, F. E., 1752. " Acta. Phys. Med.," vol. ix.,

p. 116, pi. v., fig. 4.

Palate of unknown fish. Parkinson, J., 1811. " Organic Remains," vol. iii.,

pi. xviii., fig. 12.

Ptychodus decurrens. Agassiz, L., 1839. " Poiss. Foss.," vol. iii., p. 154,

pi. xxv. b, figs. 1, 2, 4, 6-8 (nonS, 5).
Ptychodus decurrens. Owen, R., 1840-45. " Odontography," volume ii.,

pis. VIXII., XIX.

* A. S. Woodward, Proceedings of the Geological Association, vol. x.. p. 296. 1888.
t A contribution to the Vertebrate Palaeontology of Brazil, in Proc. Amer. Phil. Soc, vol. xxiii.,
p. 2. 1886.

X J. Leidy, Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. viii., p. 240, pi. xxxi., figs. 4, 5. 1877.
§ Sitzungsb. Ges. Naturf. Freunde, Berlin, pp. 1-3. 1881.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 377

Ptychodus decurrens.
Ptychodus decurrens.
Ptychodus decurrens.

Ptychodus depressus.
Ptychodus decurrens.

Ptychodus decurrens.

Ptychodus decurrens.

Ptychodus polygyrus.

Ptychodus decurrens.

Ptychodus decurrens.

Ptychodus latissimus.

Ptychodus decurrens.

Ptychodus decurrens.

Ptychodus decurrens.

Ptychodus decurrens.

Pictet, F. J., 1845. " Paleontologie," vol. ii., p. 287.
Gtiebel, C. G., 1848. "Fauna der Vorwelt," p. 333.
Dixon, F., 1850. "Foss. Sussex," p. 3C2, pi. xxx.,

figs. 7, 8; pi. xxxi., fig. 1 ; pi. xxxn., fig. 5.
Dixon, F., 1850. " Foss. Sussex," p. 363, pi. xxxi., fig. 9.
Gervais, P., 1852. " Zool. et Pal. Franc.," pi. lxxviii.,

fig. 5.

Kiprijanoff, V., 1852. " Bull. Soc. Imp. Nat. Moscou,"

vol. xxv., pt. ii., p. 490, pi. xm., figs. 4,* 5.
Quenstedt, F. A., 1852. "Handb. Petrefakt.," p. 181,

pi. xm., fig. 59.
Fischer, C. E., 1856. " Allgem. deutsche naturh. Zeit.

Dresden," N. S., vol. ii., p. 140, figs. 31-33.
Sauvage, H. E., 1872. " Biblioth. Ecole Hautes Etudes,"

vol. v., art. 9, p. 18.
Geinitz, H. B., 1875. " Palseontog.," vol. xx., pt. i.,

p. 296, pi. lxiv., figs. 24, 25.
St. Zarecznego, 1878. " Sprawozdanie Komisyi Fizy-

jograf. Galicyi," vol. xii., p. 200, pi. VHI., fig. 8.
Fritsch, A., 1878. " Reptil. u. Fische. bohm Kreide-

form.," p. 14, fig. 34.
Quenstedt, F. A., 1882. " Handb. Petrefakt.," 3rd ed.,

p. 281, woodcut, fig. 86, pi. xxi., figs. 63, 64.
Woodward, A. S., 1887. "Quart. Journ. Geol. Soc."

vol. xliii., pp. 123-130, pi. x., figs. 1-10, 13.
Woodward, A. S., 1889. " Catal. Foss. Fishes Br. Mus.,"

p. 138.

Represented by teeth from the soft white chalk of Annetorp and Oretorp in
the palseontological collection of the Riksmuseum at Stockholm. The larger
tooth is probably from the first lateral series of the upper jaw ;t it measures
0'02 m. across, and has a length antero-posteriorly of 0*017 m. ; nine ridges are
exposed, extending across the crown in nearly straight lines ; on each side they
bifurcate, and split up into a number of minute corrugations along the margins.
The nine ridges occupy an area of the surface of 0*012 m., the remaining portion
being covered with ramifying ridges increasing in number towards the margin.
The crown of the tooth is slightly convex. The root is buried in matrix.

* A doubtful tooth, subsequently assigned to P. oweni, Kiprijanoff, loc. cit., pt. ii., p. 2. 1881.
f See "Woodward's figures in Quart. Journ. Geol. Soc, vol, xliii., pi. x., fig. 4.

378 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

The second specimen is from Oretorp ; less than half the size of the one
described. The surface of the crown is flat, and exhibits a slight obliquity. Its
location appears to have been in one of the series near the lateral extremity of the
upper jaw. There are six transverse ridges, in form more or less semicircular,
which occupy nearly the whole of the crown. The space occupied by the marginal
corrugations is not large, but the characteristic folds extending from the central
portion to the periphery are quite distinct.

Formation and Locality. — Etage Danien ; Annetorp, District of Malma,
Oretorp.

Ex coll. — Riksmuseum, Stockholm.

Tooth allied to Diodon.

Ptychodus mammillaris.

Ptychodus decurrens.
Ptychodus altior.
Ptychodus mammillaris.

Ptychodus mammillaris.

Ptychodus mammillaris.

Ptychodus mammillaris.

Ptychodus decurrens.

Ptychodus mammillaris.

Ptychodus mammillaris.
Ptychodus mammillaris.

Ptychodus mammillaris, Agassiz.
(PI. xxxviii., fig. 3.)

Mantell, G. A., 1822. " Foss. S. Down," p. 231,

pi. xxxii., figs. 17, 18, 20, 21, 27, 29.
Agassiz, L., 1839. " Poiss. Foss.," vol. iii., p. 151,

pi. xxv. b, figs. 12-20 (? fig. 11).
Agassiz, L., 1839. Tom. cit.,p. 154, pi. xxv.b, figs. 3, 5.
Agassiz, L., 1839. Tom. cit., p. 155, pi. xxv. b, figs. 9, 10.
Reuss, A. E., 1845. " Verstein. bohm. Kreideform,"

pt. i., p. 2, pi. ii., figs. 11—13.
Giebel, C. G., 1848. " Fauna der Vorwelt," vol. i.,

p. 333.

Dixon, F., 1850. " Foss. Sussex," p. 361, pi. xxx.,

fig. 6 ; pi. xxxi., fig. 4.
Geinitz, H. B., 1850. " Charact. Bohm-Sachsisch.

Kreidegeb.," 2nd ed., p. 64, pi. xvn., fig. 7.
Geinitz, H. B., 1850. Op. cit., p. 64, pi. xvii.,

figs. 8-12.

Kiprijanoff, V., 1852. "Bull. Soc. Imp. Nat. Moscou,"
vol. xxv., pt. ii., p. 487, pi. xn., fig. 3; pi. xiii.,
fig. 3.

Pictet, F. J., 1854. " Palseont.," 2nd ed., vol. ii., p. 265,

pi. xxxviii., fig. 27.
Fischer, C. E., 1856. " Allgem. deutsch. naturh. Zeit.

Dresden," N.S., vol. ii., p. 139, pi. n., fig. 34.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 379

Ptychodus mammillaris. Roemer, F., 1870. " Geol. von Oberschlesien," p. 324,

pi. xxxvi. j fig. 8.

Ptychodus mammillaris. Sauvage, H. E., 1872. " Biblioth. Ecole Haute Etudes,"

vol. v., art. 9, p. 16, pi. ii., figs. 86-89.

Ptychodus mammillaris. Geinitz, H. B., 1875. " Palaeontogr.," vol. xx., pt. i.,

p. 297, pi. lxiv, fig. 26; pt. n., p. 213, pi. xl.,
figs. 23-29.

Ptychodus mammillaris. Fritsch, A., 1878. " Reptil. und Fische bohm Kreide-

form," p. 14, woodcut fig. 33.
Ptychodus mammillaris. St. Zarecznego, 1878. " Sprawozdanie Komisyi Fizy-

jograf. Galicyi," vol. xii., p. 201, pi. viil, fig. 9.
Ptychodus mammillaris. Quenstedt, F. A., 1885. " Handb. Petrefakt," 3rd

ed., p. 282, pi. xxi., figs. 61, 62.
Ptychodus mammillaris. Woodward, A. S., 1889. "Catal. Foss. Fishes in Brit.

Museum," pt. i., p. 133.

The occurrence of Ptychodus mammillaris is not common. The specimen
figured is from the white chalk of Annetorp. It is very high in the crown, with
ten or twelve transverse ridges extending across the somewhat narrow surface.
The diameter of the base is 0*015 m., equal to the height of the crown. Below the
coronal surface the sides are depressed, and covered with more or less concentric
granulated striae ; still lower the sides again expand, and the base is prominent,
and covered with fine vertical striations.

Formation and Locality. — Etage Danien : Annetorp, District of Malma.

Ex coll. — Riksmuseum, Stockholm.

Sub-Order. — A sterospondyli.

Family. — NOTIDANID-ffi.

Genus. Notidanus. Cuvier.

Body moderately elongated ; one dorsal fin opposite to the space between the
ventral and anal fins ; caudal fin large, without pit at the root ; mouth inferior ;
gill-openings — six or seven — without flaps of skin ; spiracles small, on the side of
the neck. Notochord persistent. Principal teeth consisting of a series of com-
pressed cusps, fixed upon a long base, the anterior cusp larger than the others,
with or without small denticles at its base in front. Anterior teeth of the upper
jaw clustered, awl-shaped ; a median symphysial series in the lower jaw.
Principal teeth of the upper jaw less laterally elongated, with fewer cusps than
those of the lower jaw.

TRANS. ROT. DUB. SOC, N.S., VOL. IV., PART VI. 3 I

380 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Notidanus microdon, Agassiz.

(PI. xxxviii., figs. 4—7.)

Squalus(?), tooth of. Mantell, G. A., 1822. "Foss. South Downs," p. 227,

pi. xxxii., fig. 22.

Notidanus microdon. Agassiz, L., 1843. " Poiss. Foss.," vol. iii., p. 221, pi.

xxvii., fig. 1.

Notidanus microdon. Reuss, A. E., 1846. " Verstein. bohm. Kreideform," pt. ii.,

p. 98. pi. xlii., fig. 8.
Notidanus microdon. Giebel, C. G., 1848. " Fauna der Vorwelt," vol. i.,

p. 346.

Notidanus microdon. Geinitz, H. B., 1850. " Charact. schicht. u. Petrefakt.

Sachsbohni. Kreidegeb.," 2nd ed., p. 38, pi. ix.,
fig. 2.

Notidanus microdon. Dixon, F., 1850. " Foss. Sussex," pi. xxx., fig. 30.
Notidanus microdon. Geinitz, II. B., 1875. " Palseontogr.," vol. xx., pt. ii.,

p. 210, pi. xl., fig. 1.
Notidanus microdon. Feitsch, A., 1878. 11 Rept. u. Fische bohm. Kreideform.,"

p. 12, woodcut, fig. 25.
Notidanus microdon. Woodwaed, A. S., 1886. " Geol. Mag.," Dec. m., vol. iii.,

p. 213, pi. vi., figs. 10-15.
Notidanus microdon. Woodwaed, A. S., 1888. " Proc. Geol. Assoc.," vol. x.,

p. 287.

Notidanus microdon. Woodwaed, A. S., 1889. "Cat. Foss. Fishes Br. Mus.,"

pt. i., p. 160.

Teeth of this genus occur in the collections from Lund. They are in the hard
cherty chalk from Malmstrom. Of the three specimens two are from the upper jaw,
and one from the lower. Of the former the most perfect is 0*012 m. in length
along the base of the crown. The crown consists of four cones or denticles ; the
largest is 0*005 m. in height, and on its anterior margin is a series of four or five
serrations ; the posterior denticles are much less elongated as compared with the
principal one ; all are sharply pointed. The root is large, and equal in depth to
the height of the largest cone ; the external surface of the root is concave ; the
internal surface prominent near the base of the crown, retreating lower down, so
that it forms, with the external surface, a very acute angle.

The second upper tooth is somewhat smaller, and is probably from a position

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 381

further back in the jaw. The principal cone is not relatively so much larger than
those behind, as it is in the example already mentioned.

The tooth from the lower jaw is smaller than those from the upper, but
exquisitely preserved. It is 0*010 m. in length. There is a series of nine cones
diminishing gradually and uniformly from the principal one backwards. On the
anterior margin of the first cone is a number of minute serrations. The root is
deeper than the height of the longest cone, large and massive.

In the collection from the Zoological museum at Copenhagen specimens of
N. microdon are preserved which have been obtained from the Nyere Kridt at
Stevns, in Denmark ; from Terkild-Skov, in the Island of Seeland ; and in this
museum, and also in the museum of the Geological Survey, there are numerous
specimens, mostly fragmentary, from the coraline chalk of Faxe. The average
size of the teeth from Faxe is much larger than those from the cherty chalk. The
first denticle is proportionally not so high as compared with the succeeding ones
as it is in the teeth of the upper jaw, already described, and the denticles have
generally a more erect appearance.

A single representative of this species occurs in the collection of fishes from the
Riksmuseiun of Stockholm. The specimen is 0*007 m. in length; the crown
consists of seven cones, each sharply pointed, slightly curved backwards, and
diminishing in size from the anterior principal one. The first cone is 0*002 m.
across the base, and 0*003 m. in height along the anterior border. The latter is
provided along its lower half with a series of minute but well-marked denticula-
tions. The root is not well preserved. Fragments appear to indicate that its
depth was about equal to the height of the crown. This example is from the
chalk of Limhamn, in the district of Malma, in South Sweden.

Formation and Locality. — Etage Danien : Malmstrom ; Stevns, in Denmark ;
Terkild-Skov, in the Island of Seeland ; Limhamn, in the District of Malma ; and
the coraline chalk of Faxe.

Ex coll. — Riksmuseum, Stockholm ; Zoological Museum, Copenhagen ; Uni-
versity Museum, Lund; Mineralogical Museum, University of Copenhagen.

3 12

382 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Notidanus dentatus, A. S. Woodward.
(PI. xxxviii., fig. 8.)

Notidanus dentatus. Woodward, A. S., 1886. " Geol. Mag.," vol. iii., p. 214,

pi. vl, figs. 17, 18.

Notidanus dentatus. Davis, James W., 1888. "Trans. Roy. Dublin Soc.," N.S.,

vol. iv., p. 36, pi. vi. , figs. 9-12.
Notidanus dentatus. Woodward, A. S., 1889. " Cat. Foss. Fishes in Brit. Mus.,"

pt. i., p. 159.

A single example of this species is preserved in the University's Mineralogical
Museum at Copenhagen. It is a tooth of the lower jaw, and is, unfortunately,
imperfect. Sufficient of the tooth is preserved to render its identification certain.
The part preserved consists of the principal cone, and a second, smaller one,
behind ; whilst in front are six denticles ; the length of the base of the crown is
0*02 m. ; the height of the principal cone is O011 m., that of the second one is
0*008 m. ; both are arched backwards. The denticles diminish gradually in size
forwards. They, like the cones, are robust, rounded at the point, and whilst more or
less curved backwards, are more erect than the cones. The root is not preserved.

The presence of denticles in the place of the ordinary serrated anterior margin
of the tooth serves readily to distinguish this species. The original description
by Smith Woodward was of teeth contained in a collection sent in 1876 to
the British Museum by Sir James Hector, collected at Amuri Bluff in New
Zealand. The single example of the teeth of the lower jaw possessed only three
denticles on the anterior surface, and there were three additional cones behind
the principal one. When describing the fossil fish remains of the Cretaceo-
Tertiary formations of New Zealand, I was indebted to Sir James Hector for the
loan of the Geological Survey collection from the Wellington Museum, which
contained additional and better preserved specimens than those previously
described. The characteristic denticles in front of the principal cone were found
to reach five in number, whilst the same number of cones succeeded the largest
one posteriorly. The specimen now described possessed a still larger number,
and six denticles extended anteriorly; but the general character of the tooth
appears to render its relationship beyond doubt ; and although so widely separated
from each other geographically, they are not widely separated in geological age.

No tooth has yet been identified belonging to the upper jaw, but it is not
improbable that the dissociated cusps or denticles of the teeth may exist amongst
the large number of teeth derived from the Faxe chalk.

Formation and Locality. — Etage Danien (Nyere Kridt): Faxe.

Ex coll. — Mineralogical Museum of the University of Copenhagen.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 383

Family.— SCYLLIIDJE.

Genus. Scyllium. Cuvier. " Regne Animal," vol. ii., p. 124. 1817.

First dorsal fin above or behind the pelvis ; origin of the anal always in
advance of that of the second dorsal ; upper edge of the caudal fin not serrated.
Teeth small, delicate, with a large middle cusp, and generally one or two
smaller lateral cusps ; arranged in numerous series.

Scyllium planum, Davis.
(PI. xxxvm., fig. 9.)

Teeth having the characteristics of this genus have been found in the
chalk-formation at Terkild-Skov in the Island of Seeland, and are comprised in
the collection of the Zoological Museum of the University of Copenhagen,
placed at my disposal by Prof. Dr. Liitken. They are small, and have probably
been derived from the posterior portion of the lower jaw, though two or three
teeth on each side the symphysis of the lower jaw are similar in form to the
posterior ones, and these specimens may have been so situated. They have a
breadth of 0*003 m. across the base of the crown. The principal median
cone is only equal in height to half the breadth of the tooth; on each
side is a lateral cone smaller than the median one. Each of the cones is
rounded and somewhat thick at the base, tapering rapidly to a point with a
slight curvature laterally. They are smooth. The base of the crown has a
sygmoidal curvature. The root is short, and corresponds with the base in out-
line. Its outer surface slightly retreats from the base of the crown ; the inner
surface is expanded and bulbous.

The teeth from the chalk of Seeland are very similar to some of the teeth
of the existing dogfish, Scyllium canicula, Cuv. Amongst fossil forms the nearest
relationship will probably be found with Scyllium (Thyellina) elongatum* Davis:
in this species, from the soft chalk of Sahel Alma in Mount Lebanon, the central
cusp is much longer than in these specimens ; and apart from the difference due
to the position in the mouth, the teeth have generally a more graceful and

* Trans. Roy. Dublin Society, N.S., vol. iii., p. 473, pi. xiv., figs. 2, 3.

384 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

delicate outline. Two species have been described by A. E. Reuss* from the
Planerkalk of Bohemia and Saxony, under the names of Scyllium crassiconum
and Scyllium humboldti ; these were afterwards regarded by H. B. Geinitz,*f and
his determination was accepted by Anton Fritsch,^ as distinct from the genus
Scyllium, and they were transferred to the genus Scylliodus, Agass. The latter
is considered by A. Smith Woodward § as synonymous with Scyllium, who thinks
the two species of teeth are doubtfully associated with the genus. A comparison
of the teeth now described with the plates cited, whilst exhibiting a superficial
resemblance of the coronal portion, confirms the doubt expressed by Smith Wood-
ward ; the roots of the teeth are of different form, and wanting in breadth and
definition; instead of the concave under-surface of Scyllium they are deeply
convex.

Formation and Locality. — Etage Danien : Terkild-Skov in Seeland.
Ex coll. — Zoological Museum of the University of Copenhagen.

Family.— LAMNIDiE.

Genus. Scapanorhynchus. A. S. Woodward. 1889. " Catalogue of Fossil
Fishes in the British Museum," part i., p. 35L

Syn. — Rhinognathus. Davis, J. W., 1887. " Trans. Royal Dublin Society," N.S.,

vol. iii., p. 480.

Body slender; snout much elongated. Second dorsal fin small, placed
immediately above a long anal. Caudal fin much elongated, inferiorly notched
near the extremity ; pectoral and ventral fins large. Anterior teeth with a
long slender principal cusp, and mostly with a pair of minute lateral cusps ;
postero-lateral teeth wider, central cusp shorter.

This genus was instituted, with the name Rhinognathus, and embraced a num-
ber of fishes, mostly in an imperfect condition obtained from the upper cretaceous
beds of Mount Lebanon collected by the Rev. J. F. Lewis, now in the Edinburgh and
British Museums. Unfortunately the name had been preoccupied by Fairmaire as a
name for a beetle, and a second was rendered necessary. This has been provided
by my friend Mr. A. Smith Woodward in the Catalogue of the Fossil Fishes in

*Verstein. bohm. Kreideform, pt. i., p. 4, pi. n., figs. 21, 22; pi. xn., fig. 11. (Hylodus appen-
diculatus) and pi. iv., figs. 4-8.

f Palseontographia, vol. xx., pt. i., p. 295, pi. lxv., fig. 8. 1875.

\ Eept. u. Fisehe bohm. Kreideform, p. 11, fig. 22, and p. 11, fig. 21. 1878.

§ Cat. Toss. Fishes Brit. Mus., pt. i., p. 340. 1889.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 385

the British Museum, and the genus has been found to embrace other species
from various localities. From the Swedish chalk three species are added to the
genus in the following pages.

Scapanorhynchus tenuis, Davis.

(PI. xxxviii., figs. 10-13.)

Teeth small; crown attenuate, curved inwards and at its point slightly
recurved; outer coronal surface and the apex smooth, inner surface minutely-
grooved on the basal portion ; base, expanded laterally and supporting a minute
sharply pointed denticle on each side ; outer surface slightly convex ; inner
one rounded. Height of crown of anterior tooth 0*008 m. ; width of the base
equal to half the height. Latero-posterior teeth diminish in height to O'OOI m. ;
the width of the base is equal to the height; crown curved laterally, otherwise
straighter than those in front. Root short ; prominently bulbous on inner
surface, outer one receding, inferior surface concave.

The teeth of this species, together with those of S. latus, next described, only
exist in the Stockholm Collection from Oretorp. It is not without hesitation
that it is proposed to separate them into two species. The step appears to be
justified by the marked characteristics of the two, the graceful and slender
attenuation of the crown in this species is very distinct from the broad, com-
pressed crown of the next ; the smaller dimensions of the base and the minute
lateral denticles, whilst indicating close relationship, point to a specific
difference.

Scapanorhynchus tenuis occurs in considerable abundance in the Faxekalk at
Faxe and Annetorp, and has also been found in the Saltholmskalk at Herfolge,
Grenaa, Logstor and Raunstriip. In the collection from the Zoological Museum
of the University of Copenhagen are specimens from Faxe, collected by the late
King Christian VIII. Teeth from the other localities named are comprised in
the collections of the Mineralogical Museum of the University of Copenhagen.

Formation and Locality. — Etage Danien : Faxe; Herfolge; Grenaa, in Jutland;
Logstor ; Raunstriip ; Annetorp, Scania. Etage Senonian : Calshamn ; Oretorp.

Fx coll. — Riksmuseum, Stockholm ; Mineralogical Museum and Zoological
Museum of the University of Copenhagen, Geological Museum of the University
of Lund.

386 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Scapanorhynchus latus, Davis.

(PI. xxxviii., figs. 14-17.)

Teeth broad in proportion to the height ; outer coronal surface smooth,
slightly convex, with a wide median sulcus at the base ; the lower fourth of
the height of the crown expands rapidly in breadth. Inner surface smooth and
convex. A pair of lateral denticles attached to the broad base of the crown.
Root thinner, antero-posteriorly, and the lateral bifurcations longer and deeper
than in Scapanorhynchus tenuis from the same horizon. It also differs from the
latter in the absence of grooves on the inner coronal surface ; by its less rounded
and attenuated form ; and in the larger size and greater prominence of the
lateral denticles.

This species is represented by examples from Annetorp in Sweden, in the
Mineralogical Museum of the University of Copenhagen, kindly placed at my
disposal by Prof. Johnstrup.

Formation and Locality — Etage Danien : Oretorp ; Annetorp.

Fx coll. — Riksmuseum, Stockholm; Mineralogical Museum, Copenhagen.

Scapanorhynchus gracilis, Davis.
(PI. xxxviii., figs. 18-20.)

Teeth, median cone elevated, compressed, acuminate, smooth, expanding
widely at the base, and having on each side a well developed lateral denticle
erect and acutely pointed. Anterior teeth curved sygmoidally; the curvature
of the posterior teeth is less decided, but they are inclined obliquely towards one
or other side. Height of crown 0-012 m. in an anterior example ; a latero-
posterior tooth is 0*010 m., and the breadth of the base is equal to the height;
the lateral denticles average one-fifth the height of the crown. Root short,
prolonged laterally beyond the crown, inner surface prominent, outer one con-
cave, inferior surface broad and concave. The teeth exhibit considerable variety
in form, but are all characterized by the lateral denticles occupying a position
allowing a perceptible interval between them and the median cone.

This species approaches Scapanorhynchus ? subulatus, Ag. ; it is distinguished
by the lateral denticles standing erect from the base ; those in S. subulatus are
inclined at an oblique angle outwards. The teeth situated in the several parts
of the jaws are generally similar in form to those figured of the type specimen

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 387

of the genus S. (Rhinognathus) letvisii, Davis ("Trans. Roy. Dublin Soc," N. S.,
vol. iii., p. 480, pi. xiv., fig. 4), from the cretaceous beds of Sahel Alma, Mount
Lebanon, so far as the crown is concerned, but the roots of the anterior teeth of
S. letvisii are deeply pronged; in this species they are short and widely
distended.

Formation and Locality. — Danien : Faxe or Coraline Limestone, Annetorp.
Lower Senonien : Oppmanna.

Ex coll. — Geological Museum, University of Lund.

Genus. Odontaspis. Agassiz. 1838. " Rech. sur les Poiss. Foss.," vol. iii., p. 87.

Second dorsal fin and the anal of equal size, scarcely smaller than the first
dorsal. No pit at the root of the caudal; side of the tail without keel. Teeth
of all but the few hindermost series with a long, tapering, acuminate median
cone with smooth cutting edges, base expanded with one or more pairs of lateral
denticles, larger and sharper than those of Lamna ; fourth tooth from the
symphysis upon each side of the upper jaw very small ; the teeth of the most
anterior pair in the lower jaw small and relatively very slender.

Agassiz regarded Odontaspis as a sub-genus of Lamna ; Midler and Henle
considered that it was a distinct and well-defined genus, a view since accepted
by Dr. Giinther, and more recently by A. Smith Woodward, with considerable
modification. The remains of this genus are found in the Cretaceous series of
rocks, are abundant throughout the Tertiary formations, and still continue
represented at the present time by a few surviving species.

Odontaspis acuta, Davis.

(PI. xxxviii., figs. 21-24.)

1888. " Trans. Roy. Dublin Soc," N. S., vol. iv., p. 22, pi. v., figs. 1, 2.

Teeth lanceolate, slender, curved sygmoidally, sharply pointed, expanded
base, with two pairs of lateral denticles acutely pointed and curved towards the
central crown. In the anterior teeth the crown rises to a height of 0*020 m.,
with a width at the base of 0-005 m. The root between the bases of the second
denticle on each side is double that of the base of the crown in width. The
outer coronal surface is slightly convex, more or less depressed in the median

TRANS. ROY. DUBL. SOC. N.S., VOL. IV., PART VI. 3 K

388 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

portion at the base ; the latter deeply concave. Inner coronal surface convex,
smooth, projecting at the base; lateral margins fine, smooth. Root deeply
bifurcated in the anterior teeth ; the depth of the bifurcation diminishes in
the teeth situated latero-posteriorly ; forms a prominent bulb on the inside,
with a corresponding depression externally. A median groove or sulcus
extends vertically across the prominent part of the root. The posterior teeth
have a much shorter crown, and the width of the root is greater ; the latter
in some of the teeth exceeding the former.

The teeth vary considerably in size, apparently according to age rather than
a difference in the size of the mature fish. The smaller teeth are more slender,
more acutely pointed, and have finer cutting edges than the larger ones, and
have been subject to less attrition from use. The base, whilst possessing all the
characters of the larger examples, has those characters less markedly developed,
and, agreeing with the crown, of a more attenuated nature.

Whilst the teeth now described are in many respects similar to 0. hopei, Ag.,
0. dubia, Ag., and 0. subidata, Ag., they differ from all of them in possessing two
pairs of lateral denticles, and in this character they approach Odontaspis acuta,
Davis, from the Oligocene (Oamaru) formations of New Zealand. The example
from the Danien locality of Annetorp, the highest horizon from which the teeth
have been obtained (fig. 21), is remarkably similar to the example from
Trellissic (" Trans. Roy. Dublin Soc," n. s., vol. iv., pi. v., fig. 2), whilst those
from Oppmanna more closely approximate to the specimen represented by
fig. 1 (op. cit.).

In the Danish collections this species is represented by specimens, two of
which are figured, from Faxe, Stevns, Annetorp, Luneberg, and Saltholm.
The specimen from Stevns (PI. xxxviii., fig. 23) is from the former collection
of the late King Christian VIII. of Denmark.

Formation and Localities. — Etage Danien: Annetorp; Stevns; Faxe; Luneberg.
Senoniam II. : Oppmanna.

Ex coll. — Geological Museum, University of Lund ; Riksmuseum, Stockholm ;
Mineralogical Museum, University of Copenhagen ; Zoological Museum, University
of Copenhagen.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 389

Odontaspis aeutissima, Agassiz.
(PI. xxxvin., fig. 25.)

Odontaspis aeutissima. Agassiz, L., 1843. " Poiss. Foss.," vol. iii., p. 294,

pi. xxxvu. a, figs. 33, 34.
Odontaspis aeutissima. Giebel, C. Gr., 1848. " Fauna der Vorwelt," vol. i., p. 363.
Odontaspis aeutissima. Bassano, F., 1879. " Atti. Soc. Veneto. Trent. Sci. Nat.,"

vol. vi., p. 56.

Odontaspis aeutissima. Woodwakd, A. S., 1889. " Cat. Foss. Fishes in Brit.

Mus.," pt. i., p. 374.

M. Agassiz designated under the above name teeth with a sharp point and
long, cylindrical, sharp-pointed lateral cones. The origin of the tooth which
forms the type of the species was unknown. A second example, associated with
it provisionally, was derived from the molasse of Berthoud. The tooth represented
(Plate xxxvin., fig. 25) possesses the characters ascribed by Agassiz to the species,
and differs from others already noticed from the Swedish or Danish Cretaceous
rocks. The height of the median crown is 0*008 m., and the breadth of the base
is the same. The lateral cones are 0*003 m. in height, more than one-third the
height of the crown. The root is short, retreating from the external base,
concave below, and having the form of the base of the crown. The central cone
is convex on both the inner and outer coronal surface; the lateral margins are
sharp, and the apex pointed. The lateral denticles are well developed, very long
and sharply pointed. A number of striae extend from the base towards the apex
of each. The example is rather smaller than the one described by Agassiz,
otherwise it appears to possess all its characteristics.

This species is distinguished from Odontaspis acuta, Davis, by its more graceful
and slender form ; the great size and prominence of the erect lateral denticles, of
which there is only one on each side ; as compared with the more or less curved
denticles, generally two on each side, and comparatively small size in 0. acuta,
Davis.

Formation and Locality. — Etage Danien (Myere Kridt) : Faxe.
Ex coll. — Mineralogical Museum, University of Copenhagen.

3 K 2

390 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Odontaspis faxensis, Davis.

(PI. xxxviii., fig. 26.)

Teeth small; the crowns of the anterior teeth on their external surfaces attain-
ing a height of 0*01 m. ; erect, acuminate. External coronal surface convex and
smooth ; internal one still more convex and also smooth ; very slight ridge
along each lateral margin. Base of crown expands laterally to a width of
0-012 m., and supports on each side a series of three denticles, decreasing in size
as they recede from the principal cone ; the denticles are short, conical, and
sharply-pointed. The base of the crown is concave. The root is short, with a
spongy structure, conforming in outline to that of the base of the crown.

This form is distinct from any other observed in the Cretaceous rocks of
Sweden and Denmark. It, perhaps, most closely approaches Odontaspis acuta,
Davis ; but in that species there does not appear to be more than two lateral
denticles, the second being much inferior in size to the first. In this species there
are three lateral denticles on each side ; all robust and distinct, and diminishing
gradually in size from the centre.

Formation and Locality. — Etage Danien : Faxe.

Ex coll. — Mineralogical Museum, Copenhagen University.

Odontaspis kopingensis, Davis.
(PI. xxxviii., figs. 27, 28.)

Teeth strong and robust ; crown attains a height of 0*015 m. ; on the median
line, conical and pointed ; external surface very slightly convex, smooth ; internal
surface deeply convex, rendering the crown very thick and strong. The base of
the crown is curved upwards transversely, slightly on the external face, deeply on
the internal ; it is 0*015 m. across. A single pair of lateral denticles are present.
They are triangular, and the apex of each is pointed. The root is large, deeply
forked ; the prongs well advanced on the external face ; and the median part very
prominent on the internal one.

The teeth comprised in this species appear to be rare ; a single specimen
occurs in the Riksmuseum at Stockholm from Saltholm, and another in the
Geological Museum of the University of Lund from Kopinge. It most nearly
approaches Odontaspis acuta, Davis, in general appearance ; but the triangular and
somewhat blunt character of the lateral denticles extending at right angles from
the crown, are very different from the slender acuminate denticles, curving
inwards towards the crown, of Odontaspis acuta. In this species there is no trace

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 391

of a second pair of denticles. In equally well preserved specimens of 0. acuta
there are generally two pairs.

It is significant, and confirms to some extent the isolation of this species, that
at Kopinge and Saltholm the teeth of 0. acuta have not been found; whilst in the
localities in which that species occurs in abundance this remains undiscovered.

Formation and Locality. — Etage Danien : Saltholm. Etage Senonien (zone with
Belemnites mucronatus) : Kopinge, in the District of Ystad.

Ex coll. — Riksmuseum, Stockholm ; Geological Museum, University of Lund.

Genus. Oxyrhina. Agassiz. " Recherches sur les Poissons Fossiles," vol. iii.,

pp. 86 and 276.

Second dorsal fin and the anal very small. A pit at the root of the caudal fin,
which has the lower lobe much developed ; side of the tail with a keel. Teeth
medium size, acutely triangular, compressed, slender, margins smooth, point acute,
without lateral denticles. Posterior teeth, base broad as compared with the
height, the teeth becoming smaller, shorter, and triangular.

Oxyrhina was regarded by Agassiz as nearly related to Lamna, being dis-
tinguished by its more compressed form, and the absence of lateral denticles. It
occurs fossil in the Jurassic rocks, in the Cretaceous, and most abundantly in the
Tertiary formations. The genus is represented by one existing species.

Oxyrhina mantelli, Agassiz.
(PI. xxxix., figs. 1-7.)

. Mantell, G. A., 1822. " Foss. S. Downs,"
p. 227, pi. xxxii., figs. 4, 7, 8, 10, 11, 26, 28.
. Geinitz, H. B., 1 839 (Fx. Ag.)." Charact. Schicht.
u. Petrefakt. Sachs.-bohm. Kreidegeb.," p. 12,
pi. i., fig. 4 (in part).
. Agassiz, L., 1843. "Poiss. Foss.," vol. iii.,
p. 280, pi. xxxiii., figs. 1—5 (non fig. 6), 7-9.
. Reuss, A. E., 1845. "Verstein. bohm. Kreide-
form.," pt. i., p. 5, pi. ill., figs. 1, 3, 5, 6
(? figs. 2, 4).

. Giebel, C. G., 1848. "Fauna der Vorwelt.,"
vol. i., p. 357.

Squalus zygsena ? .
Oxyrhina,

Oxyrhina mantelli,
Oxyrhina mantelli,

Oxyrhina mantelli,

392 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Oxyrhina mantelli, . . Gibbes, R. W., 1849. "Journ. Acad. Nat. Sci.

Philad." [2], vol. i., p. 202, pi. xxvu., fig. 158.
Oxyrhina mantelli, . . Dixon, F., 1850. " Foss. Sussex," pi. xxx.,

fig. 24.

Oxyrhina mantelli, . . Gervais, P., 1852. " Zool. et Pal. Francais,''

pi. lxxvi., figs. 3, 20.
Oxyrhina mantelli, . . Kner, R., 1852. " Denkschr. k. Akad. Wiss.

Wien.," vol. iii., pi. xv., fig. 3.
Oxyrhina mantelli, . . Fischer, C. E., 1856. " Allg. deutsch. naturh.

Zeit. Dresden," N. S., vol. ii., p. 141, pi. il,

fig. 43.

Oxyrhina mantelli (subinflata), Sauvage, H. E., 1867. " Cat. Poiss. Form. Second

Boulonnais" (Mem. Soc. Acad. Boulogne,
vol. ii.), p. 71, pi. in., fig. 16.

Oxyrhina mantelli, . . Roemer, F., 1870. " Geol. Oberschlesien," p. 323,

pi. xxxvi., figs. 3—5.

Oxyrhina mantelli, . . Sauvage, H. E., 1872. " Bibl. Ecole Hautes

Etudes," vol. v., No. 9., p. 21, figs. 33-35.

Otodus oxyrhinoides, . . Sauvage, H. E., 1872. Loc. cit., p. 24, figs. 39-41,

54-56.

Oxyrhina extenta, . . Leidy, J., 1873. " Ext. Vert. Fauna W. Territ "

(Rep. U. S. Geol. Surv. Ter., vol. i., pt. i.),
p. 302, pi. xviii., figs. 21-25.

Oxyrhina mantelli, . . St. Zarecznego, 1874. " Sprawozd. Komisyi

Fizyjograf. Galicyi," vol. viii., p. (126).

Oxyrhina mantelli, . . Geinitz, H. B., 1875. " Palaeontogr." vol. xx.,

pt. ii., p. 207, pi. xxxvm., figs. 1—21.

Oxyrhina mantelli, . . St. Zarecznego, 1878. Loc. cit., vol. xii.,

p. (203).

Oxyrhina mantelli, . . Fritsch., A., 1878. " Rept. u. Fische bohm.

Kreideform," p. 7, woodcut, fig. 12.
Oxyrhina mantelli, . . Woodward, A. S., 1888. " Proc. Geol. Assoc.,"

vol. x., p. 291.

Oxyrhina mantelli, . . Woodward, A. S., 1889. " Cat. Foss. Fishes

in Brit. Mus.," p. 376., pi. xvn., figs. 9-21.

Teeth " moderately robust ; outer coronal face always nearly flat, often with
large vertical wrinkles ; inner coronal face gently rounded ; root short, the
branches very divergent, thick, expanded, and abbreviated. Anterior teeth large,
triangular, and comparatively broad, the crown only gently curved outwards at

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 393

the apex ; lateral teeth having the root much wider than the main portion of the
crown, which thus exhibits a sudden basal expansion behind, and often, also, in
front,"— (A. S. W.)

The teeth of this species are smaller than those found in the English chalk,
and whilst offering great diversity in form, as exhibited in the specimens repre-
sented (Plate xxxix., figs. 1—7), the small teeth, very short and extremely broad,
which Smith Woodward * represents as occupying the posterior portion of the
jaws, are not represented. The root is deeper but less divergent laterally than
those hitherto described ; the external surface is deeply concave ; the internal
surface exhibits a correspondingly prominent convexity. The oblique teeth from
the posterior portion of the jaw do not possess so great an expansion of the
internal surface of the root as those in front ; the root is flatter, as well as more
greatly expanded laterally.

In the Danish collections this species is represented by examples from the
chalk of Saltholm and Annetorp ; all in the Mineralogical Museum.

Oxyrhina mantelli has a very wide range both in time and the area over which
its remains have been discovered. It is a common fossil in the chalk of the south
of England, and is found in the Cretaceous rocks of Sarthe, in the north of France,
in Belgium, Germany, Bohemia, Galicia, Russia, Sweden, and Denmark ; and in
America it has been found in the Cretaceous beds of Kansas, the Mississippi, and
Alabama, and a closely related species, Oxyrhina haasti, Davis, has been discovered
in New Zealand.

Formation and Locality. — Etage Danien : Saltholm ; Annetorp and Limhamn
Skane. Etage Senonien (zone with Actinomax mamillatus) : Oppmanna ; most
abundantly at the latter.

Ex coll. — Geological Museum, University of Lund ; Riksmuseum, Stockholm ;
Mineralogical Museum of the University of Copenhagen.

Oxyrhina lundyreni, Davis.

(Plate xxxix., figs. 8—13.)

The teeth comprised in this species exhibit considerable variation in form
and size. The anterior teeth are long, erect, with a slightly recurved apex ;
those which have occupied an intermediate position on the sides of the jaws are
shorter, with a broader base and greater curvature ; whilst the posterior teeth
are little more than half the length of those occupying an anterior position, and

* Cat. of Foss. Fishes in the British Museum, part, i., pi. xvii., figs. 9-21.

394 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

have a decidedly sygmoidal curvature combined with a peculiar twist outwards
towards the apex.

The length of the anterior teeth is 0*05 m., the lateral diameter, midway be-
tween the base and the apex, is 0*012 m. ; the lateral margins are produced so as
to form a fine cutting surface, and gradually converge to an acuminate apex ;
towards the base the tooth thickens, and rapidly expands to a diameter of
0*025 m. The enamelled surface is invariably smooth near the point; in some
examples the internal surface maintains this character quite to the base, whilst
the external is only slightly grooved ; in others deep channels extend from the
base far towards the apex on both the internal and external surfaces, usually more
pronounced on the latter. The channels are divided into more numerous, but
smaller, grooves at the base. The external surface of the anterior teeth is less
rounded than the internal one ; in those teeth situated posteriorly the curvature
of the two surfaces is about equally well developed. The root is not well
preserved in any of the Swedish examples, but sufficient remains on some of the
specimens to show that it was much wider than the crown, and that the internal
surface was produced so as to form a prominent median bulb. The posterior
teeth are less deeply grooved, and more rapidly and uniformly converge to a
point than the anterior ones: an average length is 0*03 m., with a lateral diameter
of 0*017 m. at the junction of the enamelled surface with the root.

A beautifully preserved specimen, showing the crown and root of a tooth,
which occupied a lateral position in the jaw, occurs in the Mineralogical Museum
at Copenhagen. It is embedded in a matrix of the coraline limestone or chalk
of Faxe. To some extent this is unfortunate, because the internal surface of the
root is hidden by the matrix ; but it is very probable that the fact of its being
attached to the matrix has preserved the crown and root intact. The examina-
tion of many hundreds of specimens has shown that the attachment of the crown
to the root is more or less fragile, and the root being apparently less easily
detached from the matrix than from the crown the two parts are rarely found
associated. It may be imagined, however, that a more careful search in the
limestone forming the matrix at the base of the crown would result in the
discovery of many other examples of the root. The height of the crown in this
specimen is 0*035 m., and its width across the exposed external surface is
0*012 m. The crown is curved slightly backwards, and at the same time
exhibits a sygmoidal curvature of the inner and outer surfaces. The outer
surface is deeply grooved from the base upwards; the inner one smooth; the
margins have a sharp cutting edge, and the apex is acuminate. The root extends
at an obtuse angle from each margin of the crown, forming a pair of processes
expanding to a diameter of 0*032 m., nearly equal to the height of the crown.
The under surface of the root is only slightly concave. The total height of the

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 395

tooth, from the anterior extremity of the base of the root to the tip of the crown,
is 0*05 mm. The root has apparently an open and porous structure.

These teeth present a considerable divergence from the usual characteristics
of the genus Oxyrhina in the long erect crown, and more especially in the wide
separation of the lateral extensions and the peculiar flat under-surface of the
root. It may at some time be found desirable to make it the type of a new
genus ; and it is not without hesitation that I have placed it as a distinct species
in the genus Oxyrhina.

This species approaches in form to that of Oxyrhina grandis, Davis, from the
Cretaceo- Tertiary beds of New Zealand. It may be distinguished by its greater
length as compared with the width, its more erect and less triangular form, and
the presence of deep grooves extending vertically on the external, and, in most
cases, on the internal, surface.

The teeth are abundant in the Faxekalk ; and numerous specimens from Faxe
are in both the Mineralogical and Zoological Museums of the University of
Copenhagen. Specimens from Saltholm also occur in each collection, and others
from Annetorp are in the former.

Formation and Localities. — Etage Danien and Etage S6ionien, in zones 1 and 2 :
Limhamn, in the District of Malm a ; Annetorp ; Faxe ; Kopinge, in the District
of Ystad ; Saltholm ; and Oppmanna, in the District of Kristianstad.

Ex coll. — Riksmuseum, Stockholm ; Geological Museum, University of Lund ;
Mineralogical and Zoological Museums of the University of Copenhagen.

Oxyrhina zippei,
Oxyrhina zippei,
Oxyrhina zippei,
Oxyrhina zippei,
Oxyrhina zippei,

Oxyrhina zippei, Agassiz.
(PI. xl., figs. 1-7.).

. Agassiz, L., 1843. " Poiss. Foss.," vol. iii. p. 284,
pi. xxxvi., figs. 49—52 ; non fig. 48.

. Pictet, F. J., 1845. " Paldontologie," vol. ii.,
p. 276.

. Giebel, C. G., 1848. " Fauna der Vorwelt,"
p. 357.

. Sauvage, H. E., 1872. " Bibl. Ecole Hautes

Etudes," vol. v., No. 9, p. 23.
. Woodward, A. S., 1889. "Catalogue of the

Fossil Fishes in the British Museum," pt. i.,

p. 392.

Teeth acuminate, slender, compressed ; enamel smooth ; with or without

TBANS. EOT. DUB. SOC, N.S. VOL. IV., PAET VI. 3 L

396 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

slight vertical grooves from the base upwards on the outer coronal surface, giving
it the appearance of a median depression ; laterally the crown exhibits a sigmoidal
curvature ; height 0'018 m. ; breadth at base of crown O009 m. ; outer coronal
surface slightly convex below, flat above ; inner surface equally convex with the
outer ; margins thin and sharp. Base of crown concave and receding on the
outer ; prominent and overlapping the root on the inner surface ; laterally wide
and expanded ; no lateral denticles. Root short, compressed antero-posteriorly
like crown ; laterally extending beyond crown, with bluntly-terminating divergent
branches; base with comparatively slight concavity. Postero-lateral teeth
broader, shorter, and more acutely pointed.

These teeth are separated from Odontaspis elegans, Ag., by the total absence
of lateral denticles, and, though superficially resembling them in form, they are
thinner and more compressed. The posterior teeth are broader and shorter, as
compared with the anterior ones, than in 0. elegans. The broadest teeth approach
Oxyrhina enysii, Davis, a species found in the Senonian formations of Oamaru and
Waipara in New Zealand. (" Trans. Roy. Dublin Society," N.S., vol. iv., p. 28,
pi. v., figs. 17-20.)

They appear to be most closely associated with, and to possess the character-
istics ascribed by Agassiz to a number of small teeth from the Greensand of
Ratisbon (" Poiss. Foss.," vol. iii., p. 284, pi. xxxvi., figs. 49-52). Agassiz was
in doubt as to the presence of lateral denticles, because the roots and a portion of
the base in the examples at his disposal were broken off. With the specimens
from the Swedish Cretaceous rocks this point is made clear ; the base and roots
are well preserved, and there are no lateral denticles. Fig. 48 (op. cit.), which
Agassiz included in this species, H. E. Sauvage considers to be the lateral denticle
of a large tooth of Otodus from the white Chalk of Villavard, which is described
as 0. spathula(u Rech. sur les Poiss. Foss. du terrain Cr^tace' de la Sarthe," " Bibl.
Ecole des Hautes Etudes," vol. v., pp. 23 and 33). The type of 0. sippei,
represented in the figures 49—52, and with fig. 48 eliminated, agrees with the
examples from Oppmanna, and the latter appear to be naturally included in the
species.

Formation and Locality. — Lower Senonian : Oppmanna, Oretorp.

Ex coll. — Geological Museum, University of Lund ; Riksmuseum, Stockholm.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 397

Oxyrhina conica, Davis, sp. nov.
(PI. xl., figs. 8-10.)

Teeth small; anterior teeth long, tapering to a sharp point, with a more or
less sigmoidal curvature ; posterior teeth broader at the base, shorter, and with a
scarcely perceptible curvature. Height of anterior tooth 0*008 m. ; breadth of
base 0*003 m. ; outer coronal surface flat on the lower, slightly convex on the
upper, part, with minute ridges at the base, which disappear higher, leaving an
even and smooth surface ; inner coronal surface convex, with similar ridges near
the base to those on the outer face ; margin of base curved upwards in centre.
Root extended beyond the base of the crown laterally, and on the inner surface ;
postero-inferior surface flattened, or slightly concave. No evidence of lateral
denticles. The root in several examples is well-preserved ; in the majority,
however, it is broken away, and only the outer shell of the tooth is preserved.

Two specimens somewhat larger, but possessing the characters of this series,
have been found at Kopinge.

The entire absence of lateral denticles on the teeth which are sufficiently well
preserved to afford evidence leads to the inference that the whole of the teeth
have probably been devoid of them. They are similar in form to a number of
teeth found in the Pondicherry Beds of India, and described by Sir Philip Egerton
in the " Quarterly Journal of the Geological Society," vol. i., p. 171. They were
imperfectly preserved, and were referred to the genus Odontaspis, with the specific
appellation, 0. constrictus. Although it is devoid of lateral denticles, Egerton con-
siders that more perfect specimens might possess them ; and he indicated a probable
relationship to Lamna [Odontaspis) subulata, Agassiz, from the Lower Greensand of
Neufchatel (" Poiss. Foss.," vol. iii., p. 296, pi. xxxvii. a, fig. 5). The latter has
well- developed lateral denticles, and a deeply-forked root. The Pondicherry
teeth have a similarly flat inferior surface to one of the specimens now
described, so far as can be ascertained from the imperfect specimens. Later,
A. Smith Woodward has transferred Odontaspis subulata, Ag., to the genus
Scapanorhynchus (" Catalogue of the Fossil Fishes in the British Museum," pt. I.,
p. 356), and has included 0. constrictus, Eg., as a synonym of the same species.

The Oretorp specimens are clearly distinct from 0. subulata, Ag., and the
absence of lateral cusps removes them from the genus Scapanorhynchus, and
indicates their relationship with Oxyrhina ; it is therefore proposed to place
them in that genus.

Formation and Locality. — Senonian : Oretorp, Kopinge (?).

Ex coll. — Riksmuseum, Stockholm.

3 L 2

398 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Vertebrce of Oxyrhina mantelli, Ag.
(PI. xxxix., fig. 14.)

Examples of vertebrae of Oxyrhina occur at Kopinge, in the Etage Sdnonien,
characterized by the presence of Belemnitella mucronata. The vertebrae have a
diameter of about 0*06 m., and are 0*015 m. in thickness. The anterior and
posterior surfaces are deeply biconcave, with the centre pierced. The concave
surfaces of the vertebra are marked by a series of concentric rings, giving a more
or less corrugated appearance, represented in the figure.

Formation and Locality. — Upper Senonian : Kopinge.

Ex coll. — Geological Museum of the University of Lund, Sweden.

Genus. Lamna. Cuvier, " Regne Animal," vol. ii., p. 126, 1817; Agassiz, L.,
1843, " Rech. sur les Poiss. Foss.," vol. iii., p. 287.

Teeth of medium size, elongated, narrow in proportion to the height, sharply
pointed, with cutting edge smooth, base expanded, lateral denticles present,
usually one pair ; root large and deeply bifurcated.

The teeth of Lamna may be distinguished from those of Otodus by being
rounder and less compressed, and having the lateral cones smaller and pointed.

Oxyrhina is devoid of lateral denticles, and is thinner and more triangular in
outline than Lamna. This latter genus first appears in the Chalk formation, and
is still existing.

Lamna elegans, Agass.
(PI. XL., figs. 11-17.)

. Brander, G., J 1776. " Foss. Hantoniensia,"

pi. ix., figs. 113-114.
. Agassiz, L., 1843. "Poiss. Foss.," vol. iii.,
p. 289, pi. xxxv., figs. 1-5. (non figs. 6, 7);
pi. xxxvu. a, fig. 50 (non fig. 58).
. Giebel, C. G., 1848. " Fauna der Vorwelt,"
vol. i., p. 359.

Dentes squali,
Lamna elegans,

Lamna elegans,

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 399

. Gibbes, R. W., 1849. " Journ. Acad. Nat. Sci.
Philad." [2], vol. i., p. 196, pi. xxv.,
figs. 98-102 (? figs. 96, 97).
. Dixon, F., 1850. " Foss. Sussex," p. 203, pi. x.,
figs. 28-31.

. Gervais, P., 1852. " Zool. et Pal. Franc.,"

pi. LXXV., fig. 3.

. Schafthautl, K. E., 1863. " Siid.-Bay. Leth.

Geogn.," p. 242, pi. lxii., fig. 6.
. Le Hou., H., 1871. " Prelim. Mem. Poiss. Tert.

Belg.," p. 12.
. Rutot., A., 1875. "Ann. Soc. Geol. Belg.,"

vol. ii., p. 34.
. Winkler, T. C, 1876. " Archiv. Mus. Teyler,"
vol. iv., p. 9.

. Vincent, G., 1876. "Ann. Soc. Roy. Malacol.

Belg.," vol. xi., p. 123, pi. vl3 fig. 4.
. Locard, A., 1877. " Faune Terr. Tert. Moy.
Corse.," p. 5.

. Winkler, T. C, 1880. "Archiv. Mus. Teyler,"

vol. v., p. 74.
. Geinitz, H. B., 1883. " Abh. Naturw. Ges. Isis

Dresden," p. 5, pi. i., figs. 4—6.
. Noetling, F., 1885. "Abh. Geol. Specialk.
Preussen u. Thiiring. Staaten," vol. vi.,
pt. iii., p. 61, pi. iv.

Odontaspis elegans, . . Woodward, A. S., 1889. " Cat. Foss. Fishes in

Brit. Museum," pt. i., p. 361.

A large number of teeth have been found in the Senonian rocks at Oppmanna,
and in other localities less abundantly, which present the characteristic appearance
of Lamna elegans, Agass., and associated with them are teeth, shorter, broader at
the base, and having the fangs of the root more widely separated, which have
probably been located in the posterior parts of the jaws of the same species.
Anterior teeth elongated and narrow, varying in size, the longest attaining a
height of 0*035 m. from the base of the enamelled crown to the point; the width
at the base is 0*007 m. The outer coronal surface is distinctly convex on the
lower half, flatter above ; smooth, except a few faint striations at the base ; inner
face deeply convex and smooth ; lateral margins produced, very thin, and sharp.
The crown is slightly curved, in some specimens scarcely perceptible. The root is

Lamna elegans

Lamna elegans,
Lamna elegans.
Lamna elegans.
Lamna elegans,
Lamna elegans,
Lamna elegans.
Lamna elegans.
Lamna elegans,
Lamna elegans,
Lamna elegans,
Lamna elegans.

400 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

rarely preserved perfect ; deeply bifurcated ; outer surface concave, retreating
directly from the base of the crown ; inner surface bulbous and prominent ;
lateral branches separated at a right angle. A minute lateral denticle is occasion-
ally preserved, tipped with enamel, and slightly separated from the principal cone.
The posterior teeth are broader, shorter, and more compressed than the anterior
ones. A tooth apparently proportionate in size to those described above is
0*025 m. in height and 0*010 m. in width ; its outer surface is flatter, and the
inner less convex, whilst its curvature is more pronounced than is that of the
anterior teeth ; the branches of the root are smaller and more widely separated,
and the inner surface is less bulbous.

This species is most abundantly represented in the Swedish collections from
the Senonian formation at Oppmanna; whilst to the Danish collections the Faxe
and Annetorp beds, in the Danian series, have contributed most largely. It may
be noted that the specimens from Faxe are very abundant, but they are generally
smaller than those from Annetorp.

Formation and Localities. — Etage Danien : Faxe Limestone : Saltholm ;
Annetorp ; Limhamn ; Malma district. Etage Sdnonien Inferieur : Kjuge, Scania ;
If o ; Oppmanna ; District of Kristianstad ; Sisseback.

Ex coll. — Geological Museum, Lund University ; Riksmuseum, Stockholm.

Lamna incurva, Davis.
(PI. xl., figs. 18-24.)

Lamna incurva, . . . Davis, J. W., 1888. " Trans. Roy. Dublin Soc,"

ser. ii., vol. iv., p. 17, pi. HL, figs. 2—5.

Odontaspis incurva, . . Woodward, A. S., 1889. " Cat. of Foss. Fishes

in the Brit. Museum," p. 372.

Teeth robust; crown smooth, with marked sigmoidal curvature ; height of
anterior teeth 0"020m. ; breadth at the base 0'005m., from which the tooth tapers
to a point ; outer coronal surface convex ; inner surface deeply convex ; the lateral
margins form a cutting edge near the apex ; nearer the base the sides of the teeth
are rounded. A comparatively small number of specimens possess a single pair
of lateral denticles, minute and sharp-pointed. The crown of the posterior teeth
is shorter than that of the anterior ones ; it is broader, more rapidly acuminate
and compressed. The root is prominently bulbous on the inner surface ; a deep
vertical notch extends along it ; lower, the root is divided into two fangs, at no
great distance apart in the front teeth, but much more widely separated in those
situated behind.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

401

This species, instituted for the reception of teeth from the Cretaceo-Tertiary
strata of New Zealand, is now found to occur in the Cretaceous system of Sweden.
The teeth from the latter locality are, however, smaller than the type specimens
from New Zealand. In addition to the examples sent from the museums in New
Zealand, several specimens are recorded by Mr. A. Smith Woodward which are
in the collections at the British (Natural History) Museum, all from localities in
New Zealand.

A small number of teeth have been obtained from the Faxe limestone at
Annetorp, and are included in the Lund collections. From Oppmanna the
number of examples is much larger ; and it is from this locality that the types
have been selected which are represented on Plate xl. There is no appreciable
difference, however, in the teeth from the two formations.

Numerous specimens are comprised in the Danish Collections, principally
derived from the Saltholmkalk.

Formation and Localities. — Etage Danien: Faxe Limestone: Annetorp; Salt-
holm ; Luneberg ; Limhamn, Skane ; Faxe. Etage Sdnonien II. : Oppmanna ;
Sisseback. Etage Se*nonien I. : Kjuge.

Ex coll. — Geological Museum, Lund University ; Riksmuseum, Stockholm (Sisse-
bach) ; and Limhamn Mineralogical and Geological Museums of the University
of Copenhagen.

Genus. Otodus. Agassiz, 1843. " Rech. sur les Poissons Fossiles," vol. iii.,

p. 266.

This genus is defined by Agassiz as occupying an intermediate position
between Carcharodon and Lamna or Oxyrhina. It may be distinguished from
Oxyrhina by the presence of a well-defined lateral denticle on each side the
median cone, more frequently rounded than compressed or pointed. The median
cone is broad and compressed ; similar in form to that of Oxyrhina. In Lamna
and Odontaspis the lateral denticles are smaller, more cylindrical and pointed,
and the teeth generally more elongated. The absence of marginal serrations
serve to distinguish this genus from Carcharodon. The root is largely de-
veloped and thick, but is devoid of the deep lateral projection which distinguishes
Lamna.

This genus is found abundantly in the Cretaceous and Tertiary formations,
but, so far as known, has since ceased to exist.

402 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Otodus appendiculatus, Agassiz.

(PI. XLI., %S. 1-11.)

Dent de Squale, . . . Faujas St. Fond, 1799. " Hist. Nat. Mt. St.

Pierre de Maestricht," p. 110, pi. xviii.,
fig. 2.

Squalus mustellus (?), . . Mantell, G. A., 1822. " Foss. S. Downs,"

pi. xxxii., figs. 2, 3, 5, 6, 9.

Squalus cornubicus, . . Geinitz, H. B., 1839. " Charact. Schicht. u.

Petrefact. bohmsachs. Kreideform.," pp. 11,
12, pi. i., figs. 3, 5.

Odontaspis rhaphiodon, . . Geinitz, H. B., 1839. Op. cit., pp. 11, 12,

pi. i., figs. 3, 5.

Otodus appendiculatus, . . Roemer, F., 1841 (ex Agassiz MS.). "Nordd.

Kreidegeb.," p. 107.

Otodus appendiculatus, . . Agassiz, L., 1843. " Poiss. Foss." vol. iii.,

p. 270, pi. xxxii., figs. 1—25.

Otodus appendiculatus, . . Reuss., A. E., 1845. " Verstein. bohm. Kreide-
form.," pt. i., p. 5, pi. in., figs. 23—29
(? figs. 30, 31, non fig. 22).

Otodus appendiculatus, . . Giebel, C. G., 1848. " Fauna der Vorwelt

Fische," p. 353.

Otodus basalis(?), . . Giebel, C. G., 1848. " Fauna d. Vorw. Fische,"

p. 354.

Otodus appendiculatus, . . Gibbes, R. W., 1849. " Journ. Acad. Nat. Sci.

Philad. II.," vol. i., p. 199, pi. xxvi.,
figs. 138-140.

Otodus appendiculatus, . . Dixon, F., 1850. "Foss. Sussex," pi. xxx.,

fig. 25 ; pi. xxxi. , fig. 17.

Otodus latus (?), . . . Gervais, P., 1852. " Zool. et Pal. Franc.,"

pi. lxxvi., fig. 23.

Lamna acuminata (?), . . Gervais P., 1852. Op. cit., pi. lxxvi., figs

12-24.

Otodus basalis (?), . . Kiprijanoff, V., 1854. " Bull. Soc. Imp. Nat.

Moscou," pt. ii., p. 388, pi. il, figs. 31-38;
pi. in., figs. 1—10.

Otodus appendiculatus, . . Hebert, E., 1852. "M6n. Soc. Geol. France"

[2], vol. v., p. 355.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

403

Otodus appendiculatus, . . Fischer, C. E., 1856. " Allg. deutsche. Naturli.

Zeit.," N.S., vol. ii., p. 141, pi. n., figs. 38-44,
59.

Otodus appendiculatus, . . Pictet and Campeche, 1858. " Foss. Terr.

Cr&ace" St. Croix," p. 82, pi. x., figs. 3, 4.
Otodus appendiculatus, . . Roemer, F., 1870. " Geol. von Oberschlesien,"

p. 323, pi. xxxvi., fig. 6.
Otodus appendiculatus, . . Sauvage, H. E., 1872. " Bibl. Ecole Hautes

Etudes," vol. v., No. 9, p. 26, pi. n.,

figs. 57-59.

Lamna acuminata, . . Sauvage, H. E., 1872. " Bibl. Ecole Hautes

Etudes," vol. v., No. 9, p. 34, pi. il,
figs. 73-75.

Otodus appendiculatus, . . St. Zarecznego, 1874. u Sprawozd. Komisyi

Fizijograf. Galicyi," vol. viii., p. (125 \

Otodus appendiculatus, . . Geinitz, H. B., 1875. " Palaeontogr.," vol. xx.,

pt. i., p. 294, pi. lxv., figs. 6, 7 ; pt. ii.,
p. 208, pi. xxxviil, figs. 37-54.

Otodus appendiculatus, . . St. Zarecznego, 1878. Loc. cit., vol. xii., p. (203).

Otodus appendiculatus, . . Etheridge, R., jun., 1888. " Proc. Linn. Soc.

N. S. Wales" [2], vol. iii., p. 158, pi. iv.,
fig. 1.

Otodus appendiculatus, . . Nikitin, S., 1888. " Mem. Comite* Gex>l.," vol. v.,

No. 2, p. 60, pi. v., figs. 3-5.

Lamna appendiculata, . . Woodward, A. S., 1889. " Catal. Foss. Fishes in

the Brit. Museum," pt. i., p. 393.

Teeth medium size ; median cone of anterior teeth high, robust, in form of
isosceles triangle ; point slightly recurved outwards ; height of large example
0*030 m. ; breadth at base of cone 0'017 m. ; outer coronal surface slightly convex
or flat ; median basal portion depressed, with or without grooves ; inner coronal
surface convex, smooth ; lateral margins constitute a sharp cutting edge. Single
pair of divergent lateral denticles broad, compressed, pointed ; breadth of base,
including lateral denticles, 0*030 m. Postero-lateral teeth as broad as long ;
median cone more or less triangular; lateral denticles larger comparitivcly than
those of the front teeth. Root larger, with deep lateral prongs ; external surface
depressed and hollow ; internal one prominently convex.

In the collection sent, from the Zoological Museum at Copenhagen there are a
large number of teeth from the Chalk of Faxe which undoubtedly belong to this
species. Associated with them are still larger numbers without lateral denticles,

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART. VI. 3 M

404 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

and for the most part without root. The latter do not present any character
which will distinguish them from the median cusp of Otodus appendiculatus, Ag.,
but are so similar in size and form that there can be no other course but to include
them, although without lateral denticles, in the same species. Had they been
found dissociated from the undoubted teeth of Otodus they would have been con-
sidered as teeth of Oxyrhina mantelli, Ag. ; and it may still be possible that more
minute investigation in the strata at Faxe will prove that the latter is their proper
location. The peculiar nature of the matrix, and the manner in which it is
cemented together, renders the extraction of the fish-teeth in a perfect condition
difficult ; and the lateral portions, as well as the base of the tooth, are very likely to
be broken away unless especial care is exercised.* Specimens to which the
matrix is still attached, in nearly every instance exhibit one or both the lateral
denticles in situ ; but it is easy to conceive that if the tooth were extracted from
the limestone the median large crown would be broken off without the lateral
cones and base. If the teeth have been collected by operatives unskilled in this
branch of palaeontology, they would probably not exercise the care necessary
to obtain the specimens perfect, and this may account for their present
condition.

The teeth from Oretorp are smaller in size than those from the remaining
localities, and in a very large proportion of them the root is broken off, the
median cone alone remaining. A few, however, are more perfect, and the root
and lateral denticles are preserved.

Sauvage (" Biblioth. des Hautes Etudes," vol. v., p. 27) doubts whether all the
teeth figured by Agassiz (" Poiss. Foss.," vol. iii., pi. xxxn., figs. 1—25) should be
included in the same species, and considers that several species are confounded
together. Agassiz himself appears to have held the same opinion, and states that
among the number of teeth figured there are several which differ from each other
more than certain species which have been described as distinct. The teeth
represented by figs. 19—25 were probably a distinct species ; and doubt was
expressed as to whether figs. 17 and 18 were not also different. If fig. 7 be
eliminated along with fig. 9, the latter being possessed of two pairs of lateral
denticles, and the former being more of the form of Odontaspis than that of
Otodus, the remaining figures seem to possess closely related characters ; and,
when so curtailed, the larger number of specimens from the Swedish Cretaceous
system falls naturally into association with this species. Mr. A. Smith Woodward
records the occurrence of a tooth resembling the original of fig. 7 (Agassiz, torn,
cit.) associated with a group of about twenty-five others in a block of chalk from

* The three specimens on the tablet in the collection of the Zoological Museum, No. 305, may be referred
to as exhibiting the character here indicated.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 405

the neighbourhood of Maidstone. In the same group is a small tooth which may
possibly be regarded as the third tooth of the upper jaw, closely resembling a
tooth assigned to Lamna subulata by H. G. Geinitz (" Palaeontogr.," vol. xx.,
pt. ii., pi. xxxvm., fig. 31).

In the Swedish collections the most numerous specimens are obtained from
Oppmanna, in the lower stage of the Senonian beds, characterized by the
presence of Actinocamax mammillatus, and are now located in the Museum of the
University of Lund. In the Danish collections the best locality is Faxe, the
Chalk of that district yielding large numbers of teeth in a very beautiful state of
preservation. Several of these have been selected for illustration. The Uni-
versity Zoological Museum possesses a series from the Saltholmkalk, which formed
part of the original museum collected by King Christian VIII.

Associated with the teeth are vertebrae which in all probability belonged to
the same genus.

Swedish.

Formation and Locality. — Etage Danien : Annetorp. Etage Sdnonien II. :
Oppmanna. Faxe Coralline Limestone ; Oretorp ; Balsberg. S^nonien I. :
Kopinge ; Kjuge.

Ex coll. — Geological Museum, University of Lund, from all the localities
except Oretorp and Kopinge. The teeth from Oretorp and Kopinge are from
the Riksmuseum, Stockholm.

Danish.

Formation and Locality. — Etage Danien : Skillingsbro' ; Saltholm ; Stevns ;
Herfolge; Hjern; Annetorp; Faxe; Terkild-Skov in Seland; Ignaberga,
Scania.

Ex coll. — Mineralogical Museum and Zoological Museum of the University of
Copenhagen.

Otodus limhamnensis, Davis, sp. nov.
(PI. XLI., figs. 12.)

The teeth which are included in this species are distinguished by the great
strength and thickness of the crown, and by the large and prominent develop-
ment of the root. The crown is 0-030 m. in height ; the width of the base is
0'020 m. ; a lateral extension of the root beyond the width of the crown increases

312

406 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

its width to 0*030 m., and enables it to support on each side a lateral denticle.
The outer coronal surface is convex in the median and upper parts ; the lower
part is depressed and flat ; a slight median ridge extends from the base one-third
of the height ; enamel smooth. The inner coronal surface is deeply convex,
expanding outwards at the base, without folds or striations. Lateral margins
trenchant, continuous with the lateral denticles ; the base of the enamel rises in a
gentle curve from each side to the centre on both the inner and outer surface.
The lateral denticles are strong, convex on each surface, rather more so on the
inner than the outer one ; margin with a sharp edge ; point inclined away from
the crown. Root large and massive, laterally extending beyond the enamelled
surface. The outer surface is depressed from the base of the crown ; from the
inner coronal surface the root projects very boldly, extending forward nearly
horizontally, the diameter being 0*016 m. The inferior surface of the root is
deeply concave in the middle, with lateral projections extending downwards at an
acute angle.

The specimens referred to this species are from Limhamn, in the district of
Malma, in the Danien formation. They approach, on the one hand, Otodus
appendiculatus, Agassiz, and on the other, Otodus spathula, Sauvage ("Bibl. Ecole
Hautes Etudes," vol. v., No. 9, p. 32, pi. i., figs. 27-32). The latter is from
the white chalk occurring at Villavard, in the Sarthe. The crown is similar in
form to the species now described. The characteristic of the Sarthe species con-
sists in the lateral cones being separated from the principal one ; the enamel of
the latter does not extend to the former. This feature separates it clearly from
the Limhamn type, in which the lateral cones are connected by the continuity of
the enamel with that of the crown ; the downward projections of the root are
also much deeper than in the examples described by Sauvage ; and the root is
altogether much thicker. The latter character serves also to distinguish the
species from 0. appendiculatus, Ag. The crown of the tooth is stronger and thicker,
and more convex on both the inner and outer surfaces.

Formation and Locality. — Etage Danien : Linhamn, Skane.
Ex coll. — Riksmuseum, Stockholm.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 407

Otodus obliquus, Agassiz.
(PL xli., fig. 13.)

Dens squali, . . Beandee, G., 1766. " Foss. Hautoniensia," pi. ix.;

fig. 115.

Otodus obliquus, . . Agassiz, L., 1843. " Poiss. Foss.," vol. iii., p. 267,

pi. xxxi. ; pi. xxxvi., figs. 22—27.

Otodus lanceolatus, . Agassis, L., 1843. " Poiss. Foss.," vol. iii., p. 269,

pi. xxxvn., figs. 19-23.

Otodus obliquus, . . Giebel, C. G., 1848. "Fauna der Vorwelt. Fische,"

p. 355.

Otodus obliquus, . . Gibbes, R. W., 1849. " Journ. Nat. Science, Philad.,"

ser. 2, vol. i., p. 199, pi. xxvi., figs. 131-137.
Otodus obliquus, . . Dixon, F., 1850. " Foss. Sussex," p. 204, pi. x.,

figs. 32-35; pi. xv., fig. 11.
Otodus obliquus, . . Moeeis, J., 1854. " Cat. Brit. Foss.," p. 335.
Otodus obliquus, . . Dames, W., 1883. u Sitzungsb. k. Preuss. Akad. Wissen.,"

pt. i., p. 145, pi. in., fig. 6.
Otodus obliquus, . . Geinitz, H. B., 1883. " Abh. Naturw. Ges. Isis,

Dresden," p. 6, pi. L, figs. 12-18.
Carcharodon obliquus, . Noetling, F., 1885. " Abh. Geol. Specialk. Preussen u.

Thiiring. Staaten.," vol. vi., pt. iii., p. 84, pi. vi.,

figs. 4—6.

Otodus obliquus, . . Davis, J. W., 1888. " Trans. Roy. Dublin Soc," ser. il,

vol. iv., p. 15, pi. vii., fig. 16.
Lamna (?) obliqua, . Woodwaed, A. S., 1889. " Cat. Foss. Fishes Brit. Mus.,"

pt. i., p. 404.

The tooth represented by the figure indicated above is the only one occurring
in the collections examined. It is from the Zoological Museum of the University
of Copenhagen, and was obtained from the Cretaceous formation at Rugaard, near
Grenaa, in Jutland. The tooth is strong and robust; the crown is 0"03 m. in
height ; the width of the base of the crown is 0*033 m., of which one-third is
occupied by the lateral denticles. The outer coronal surface is moderately convex
and smooth ; the inner face is well-rounded and also smooth. The lateral
margins and apex thin out to a fine cutting edge. Lateral denticles, one on each
side, are broad, smooth, and acuminate. The root is very thick ; and on the inside
the median portion forms a prominent and expanded boss ; the outside retreats

408 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

from the base of the crown ; the under surface is deeply concave, the lateral
prongs extending and forming deep projections.

This tooth is indistinguishable from the teeth of Otodus obliquus, Ag., of the Red
Crag of the Eastern Counties of England ; and although not previously recorded
from measures lower than the Tertiaries, there appears no alternative but to
place it with this species. Its nearest relation amongst the Scandinavian fishes is
with Otodus appendiculatus, Agass. ; but from that species it is distinguished by the
thickness and rounded form of the crown, and by the great inner extension of the
root.

Formation and Locality. — Kridt formation : Rugaard, v. Grenaa, Jutland.
Ex coll. — Zoological Museum, University of Copenhagen.

VERTEBRA OF OTODUS.

(PI. xl., figs. 25, 26, 27; pi. xlil, figs. 1, 2, 21.)

Vertebrse of this genus occur with considerable frequency ; they vary in size,
and probably belonged to more than one species. The larger examples measure
0'055 m. in diameter, and the smaller ones 0*015 m. The internal structure
possesses the characteristics represented by Professor Carl Hasse * in the
Plagiostomi asterospondyli, the calcifications between the anterior and posterior
concave surfaces assuming a radiating or star-like arrangement in vertical section.
The vertebrae of Otodus are classed with Ginglymostoma and Crossorhinus in the
Scylliolamnidae.

Formation and Locality. — Etage Danien : Faxe. Etage Sdnonien : Kopinge,
Ignaberga.

Ex coll. — Zoological Museum, University of Copenhagen ; Geological Museum,
University of Lund.

SERIES OF SMALL VERTEBRAE.
(PI. XL., figs. 28-32.)

A number of vertebras occur in the collection from the Riksmuseum at Stock-
holm which have been found in the Chalk beds at Kopinge. They are in some
instances beautifully preserved, and probably belong to some of the smaller
genera of Lamnidae.

Formation and Locality. — Etage Sdnonien (zone with Belemnites mucronatus):
Kopinge, in the district of Ystad.

Ex coll. — Riksmuseum, Stockholm.

* "Das natiirliche System dor Elasmobranchier auf Grundlage des Baues und der Entwicklung ihrer
Wirbclsaule," p. 209, pi. xxvn., figs. 26, 39, 40. 1882.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 409

Coprolite (?) Otodus.
(PI. xl., fig. 33.)

The coprolite figured is from the Museum at Stockholm, and is the only-
example occurring in any of the collections. It closely resembles the coprolite
of Macropoma, and similar objects found in the Cretaceous formation of Bohemia
were identified by Reuss* as the coprolites of Macropoma mantelli, Ag. Fritschf
expresses his conviction that, so far as the specimens represented on pi. v., figs. 1-5,
by Reuss, were concerned, they were the coprolites of a Selachian, and probably
belonging to Otodus appendiculatus, Ag. Some of the coprolites exhibited peculi-
arities of form which could not be attributed to Macropoma; and, further, there
was no evidence of the presence of Macropoma in the beds from which the
coprolites were obtained. The Swedish and Danish Chalk offers a parallel case.
Taken independently, it is probable that the coprolite now figured might be
associated with Macropoma ; but no evidence of the scales or bony skeleton of
this genus has been found, and the absence of such evidence leads to the
inference that the coprolite may, with a reasonable amount of probability, be
referred to Otodus appendiculatus, the remains of which are abundant.

Formation and Locality. — Etage Senonien : Faxe.

Ex coll. — Riksmuseum, Stockholm.

Genus. Carcharodon. Mullee and Henle, 1841. " Syst. Beschreib.

Plagiostom.," p. 70.

Second dorsal fin and the anal very small. A pit at the root of the caudal
fin, which has the lower lobe well developed ; side of the tail with a keel. Teeth
large, erect, compressed, triangular, without basal cavity, margin serrated.

* " Ver stein, der Bohmischen Kreideformation," p. 11, pi. v., figs. 1-8 ; pi. rv., figs. 68-80. 1845.
f " Reptil. u. Fischeder Bohmischen Kreideformation," p. 18. 1878.

410 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Carcharodon rondeletii, Muller and Henle.

(PI. XLI., fig. 14.)

Carcharodon rondeletii, . . Muller and Henle, 1841. " Syst, Beschreib.

Plagiostom.," p. 70.

Carcharodon sulcidens, . . Agassiz, L., 1843. " Poiss. Foss.," vol. iii.,

p. 254, pi. xxx. a, figs. 3—7.

Carcharodon sulcidens, . . Gibbes, R. W., 1848. " Journ. Acad. Nat. Sci.

Philad.," ser. n., vol. i., p. 147, pi. xxi.,

figs. 52, 53.

Carcharodon sulcidens, . . Gemmellaro, G. G., 1857. " Atti. Acad.

Gioenia Sci. Nat.," ser. il, vol. xiii.,
p. 308, pi. iv.a, figs, 5-7.

Carcharodon tornabene, . . Gemmellaro, G. G., 1857. Tom. cit, p. 309,

pi. i.a, fig. 12.

Carcharodon etruscus, . . Lawley, R., 1881. " Studi comp. Pesci Foss.

coi viventi gen. Carcharodon, Oxyrhina,
e Galeocerdo.," p. 17, pis. n., in., v.
(Carcharodon), pi. iv. (Carcharodon),
fig. 2.

Carcharodon rondeletii, . . Woodward, A. S., 1889. " Cat. Foss. Fishes

in Brit. Museum," pt. i., p. 420.

A portion of a tooth, probably belonging to this species, has been found in the
Chalk at Faxe, and is now in the collection of the Mineralogical Museum at the
University of Copenhagen. A part of the specimen has been cut away, appa-
rently for the purpose of making microscopical sections ; the remaining part
exhibits the left half of the crown and root. The crown is 0'03m. in height;
the length of the margin of the tooth, including the root, is 0"045 m. The crown
is thin and compressed ; the outer surface is slightly convex, almost flat, with the
apex slightly curved outwards. The inner surface is convex. The crown is
widely expanded, its breadth equalling its height. The margin is serrated ; there
is no evidence of lateral denticles. The root, like the crown, is compressed ;
spongy in structure. The inferior surface concave, and conforming in outline to
the base of the crown.

This specimen agrees in all essential particulars with the specimens described
by L. Agassiz as Carcharodon sulcidens, Ag., from the Tertiary strata of Italy.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 411

These specimens, and others, have since been studied by R. Lawley, and the
results of his investigations have shown that the species is the same as C. rondeletii,
M. & H., which still exists in the tropical seas. Smith "Woodward has ac-
cepted the views held by Lawley, and regards the Italian fossil fish remains as
pertaining to the existing species. Should all these determinations prove correct,
the occurrence of a representative of the existing species in the Chalk of Faxe will
be interesting.

Formation and Locality. — Etage Danien (Nyera Kridt) : Faxe.
Fx coll. — Mineralogical Museum, University of Copenhagen.

Genus. Corax. Agassiz. 1843. "Rech. sur les Poiss. Foss.," vol. iii., p. 224.

Known only by the teeth, and confined to the Cretaceous rocks. Small or
medium size ; compressed, and more or less triangular ; mature specimens
generally with uniform marginal serrations ; in young examples the serrated edge
is sometimes wanting. Root large, slightly hollow beneath.

They resemble to some extent the teeth of Galeus and Galeocerdo ; but Agassiz
has pointed out that they are readily distinguished by the microscopical structure
of the teeth ("Poiss. Foss.," vol. iii., p. 224), which in this genus are solid, as in
the Lamnidse ; whilst the teeth of Galeocerdo and Galeus agree with the remain-
ing CarchariidaB in being hollow in the interior. Corax is readily distinguished
from Galeus by the smooth anterior margin of the teeth of the latter ; and those
of Galeocerdo are very strongly crenulated on the basal extremity, whilst the
serrations of the crown are comparatively feeble. The solidity of the structure of
the teeth of Corax recalled to Agassiz the similarity to Notidanus, and M. Sauvage
(" Biblioth. de l'Ecole des Hautes Etudes," vol. v., No. ix., p. 39), after considering
the superficial and microscopical relationship of Corax with Galeus and Notidanus
was disposed to consider that structure was of greater importance than external
form, and that, in a truly natural classification, Corax will be found to have a
greater affinity with Notidanus. Corax, so far as is known, became extinct with
the Cretaceous period, and it remains to be seen whether its descendants must
be looked for amongst the Tertiary and existing Galeus and Galeocerdo or in the
Notidanidae.

THANS. ROT. DTJBL. SOC. N.S. VOL. IV., PART VI.

412

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Corax lindstromi, Davis, sp. nov.

(PI. XLIL, figs. 3—11.)

Teeth of medium size, varying much in height and breadth of crown, but all
possessed of an arched anterior margin, extending far down, and enveloping the
base or root, and a more or less deep indent of the posterior margin. A large
example has a breadth across the base of the crown of O022 m. ; the height of the
crown on the external surface is 0*012 m., and on the internal one 0-009 m. The
size varies to specimens having only one-third these measurements. The external
surface of the crown is slightly convex in the median part, flat towards the
margins ; slight folds in the enamel rise from the base, and disappear higher on
the crown. Internal surface convex, with delicate, broad folds near the base.
Line dividing the crown from the base deeply arched upwards on internal surface,
less so on the external one. Anterior margin boldly arched, and extending over
the root. Posterior margin straight, or with a slightly sigmoidal curvature, on
upper part ; the lower part extends thence more or less horizontally, forming a
deep indent, at an angle varying from a right-angle to one which is obtuse. The
margins are uniformly and finely serrated over their whole length ; the apex
of the crown is acuminate, the root is large, equal in breadth to the crown, flat
on the external surface, convex on the internal one, inferior surface slightly
concave.

The study of the large series of specimens of the genus Corax in the British
Museum has induced Mr. A. Smith Woodward to reduce the number of species to
three, viz. Corax pristodontus, Ag., C. falcatus, Ag., and C. affinis, Ag. The last
is a small species, the principal teeth of which have a much elevated, slender
crown, with a notch on both the posterior and anterior margin, producing a broad
posterior, and a narrow anterior denticle. Corax falcatus is medium sized ; the
crown is elevated, not so much so as in C. affinis ; the anterior coronal margin is
arched, but not so much as in the Corax pristodontus ; the posterior coronal margin
is more or less deeply notched, and the base of the enamel on the external sur-
face is comparatively straight. Corax pristodontus has a very broad base, a large
tooth, has little or no indentation on the posterior margin, and the anterior
margin of the crown is prolonged for a considerable distance over the root ; the
base of the crown on the external surface being thus rendered much arched, a
feature not very well exhibited in the specimens figured by Agassiz ("Poiss. Foss.,"
vol. iii., pi. xxvi., figs. 10—13). The teeth now described from the Lower
Senonian strata of Ifo and Oretorp appear to occupy an intermediate position

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 413

between Corax pristodontus and Corax falcatus. They have a well-marked indenta-
tion, or notch, on the posterior margin, and at the same time exhibit a long,
arched extension of the anterior margin over the root, and the base of the crown
on the external surface is rounded. They may either be considered as a connect-
ing link uniting the two species, or as an independent species.

M. Reuss ("Verst. der. Bohmischen Kreideform," 1845, pt. I., p. 3) has
expressed the opinion that only one species of Corax existed during the Cretaceous
era, to which he gave the name C. heterodon, including in it C. Jcaupii, C. falcatus,
C. appendiculatus, and C. affinis, of Agassiz. M. Herbert (" Memoires de la Soc.
Geol. de France," 1854, ser. n., vol. v., p. 353) arrived at a similar conclusion after
a very careful study of a large number of specimens from the Chalk of Meudon
and Cotentin, embracing all the variations between Corax kaupii and C. pristo-
dontus, and he suggested the name Corax pristodontus, Ag., as being the earliest,
under which all the others should be affiliated ; whilst M. Pictet was led to
remark (Pictet et Campiche, "Foss. Crdtace" de Sainte Croix," 1858, ser. il, p. 80)
that there was very small probability that so many and varied forms could be
associated on the jaws of the same fish ; and M. Sauvage says that it is not to
be supposed that only a single species had lived in the Cretaceous seas from the
epoch of the Gault to that of the Maestricht beds (" Bibliothde l'Ecole desHautes
fitudes," 1872, vol. v., art. 9, p. 40).

In the midst of so many learned opinions, a clear and definite judgment on this
difficult and intricate set of phenomena is impossible. There may be some hope
that a complete dental series may be found which will exhibit the natural
arrangement; but until this happens all classification must of necessity be
provisional. Whilst recognizing the possibility that many of the specimens
now supposed to represent separate species may ultimately be proved to have
been associated in the same jaws, it may be advantageous to consider them
as distinct until material shall be acquired which will render their determination
certain.

Formation and Locality. — Etage S^nonien Superieur : Kopinge ; Etage Se'nonien
Inferieur (zone with Actinocamax mammillatus, Nills.) : If 6; Oretorp ; Ignaberga;
Oppmanna; Balsberg,

Ex coll. — Riksmuseum, Stockholm ; Geological Museum of the University of
Lund.

3H2

414

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Order. — HOLOCEPHALI.
Family— EDA P HOD ON TIDiE, Owen.
Genus. Ischyodus, Egerton.
Ischyodus brevirostris y Newton (Ag. MS.).
(PI. xlii.j figs. 12-15.)

Chimsera (Iscliyodon) brevirostris, Agassiz, L., 1843. " Poiss. Foss.," vol. iii.,

p. 344 (name only).
Ischyodus brevirostris, . . Egerton, P. de M. Geey, 1843. " Proc. Geol.

Soc.," vol. iv., p. 156 (name only).
Ischyodus brevirostris, . . Morris, J., 1854. " Cat. Brit. Foss.,"

p. 330.

Ischyodus brevirostris, . . Newton, E. T., 1876. "Quart. Journ. Geo-
logical Soc." vol. xxxii., p. 326, pi. xxi.,
figs. 1—5.

Ischyodus brevirostris, . . Newton, E. T., 1878. " Chimseroid Fishes,

Brit. Cret. Rocks (Mem. Geol. Survey),"
p. 27, pi. ix.

Ischyodus brevirostris, . . Davis, J. W., 1888. " Trans. Roy. Dubl.

Soc," 2nd ser., vol. iv., p. 42. pi. vii.,
figs. 10-13.

Several specimens of this ChimEeroid occur in collections from the Lund Uni-
versity. Mostly they are in a fragmentary condition. The specimen (fig. 12) is
an example of the left mandible, and the most perfect in the collection. The
posterior part of the jaw is defective and broken ; this is the case with all the
specimens, and has been explained by Newton. As the anterior parts of the jaws
are worn away, they are constantly pushed forward by the growth of new
matter behind, and the posterior parts always growing, and consequently being
imperfectly ossified, they are readily broken and damaged. The anterior margin
and the sinuous indentations which characterize it can be inferred, though the
margin is defective. The symphysial margin is slightly convex. The oval
surface of the tooth is divided between raised portions of dentinal substance and

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 415 •

intermediate smooth hollows. The dentinal substance, which is considered by
Newton to be the representative of teeth, is arranged in a series of lamellse, or
plates, near the anterior beak of the tooth ; but the larger number of teeth further
back are composed of small tubes, generally perpendicular to the surface, around
which the dentinal substance is deposited. The large central tooth has this con-
struction. The teeth vary considerably in outline in the several specimens, and
the jaws also offer no small variety. Compared with the English Gault specimens,
this one is longer from front to back in proiDortion to the breadth from the sym-
physis to the opposite margin. In this respect it also differs equally from the
examples from the Amuri Bluff beds in New Zealand.

Some specimens of smaller size also occur in the collection at the Lund Uni-
versity ; they are imperfect, and the specific characters not well preserved. The
specimen represented by fig. 14 may be a part of the pre-maxilla, and the one forming
the subject of fig. 15 the anterior portion of the mandible. The structure of both is
open and porous ; the external surface is hard, smooth, and somewhat polished ;
the inner surface presents a more or less granulated appearance, due probably to
the calcification of the extremities of the tubes forming the dentinal surface.

Formation and Locality. — Etage Senonien, No. 2 : Oppmanna ; Etage Senonien,
No. 1: Kopinge (figs. 12, 13). Senonien (zone with Actinocamax mammillatus,
Nills.) : If 6 ; Ignaberga (figs. 14, 15).

Ex coll. — Geological Museum of the University of Lund.

Order.— GANOIDEI.

Family.— PYCNODONTIDiE.

Genus. Ccelodus, Heckel. 1849. " Beitrage zur Kenntniss der Fossilen
Fische Oesterreichs," pt. I., p. 202, pi. I., fig. 6.

Pycnodus, . . . Agassiz, L., 1843. (in part.) "Kech. sur les Poiss.

Foss.," vol. ii., pt. II., p. 183.

This genus is distinguished by the teeth being hollow in the centre of the
crown (not due to attrition), and the elongated teeth being raised towards each

416 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

extremity. Teeth of the upper jaw in five rows ; median row large, transversely
elliptical, side rows with small roundish or oval teeth. Each ramus of lower jaw
with three rows of teeth ; outer row small and round ; middle row somewhat
larger, transversely oval ; inner row large, very broad, but short, elliptical, smooth,
faintly arched, or flat. Cutting-teeth chisel-shaped.

Zittel has reconstituted the genus Ccelodus ( " Handbuch der Palseontologie,"
vol. iii., p. i., p. 249), and along with the species described by Heckel has included
all those teeth previously described as species of Gyrodus and Pycnodus, possessing
the characters given above, amongst others the types of a number of teeth
occurring in the Swedish Cretaceous rocks, which Agassiz described as Pycnodus
subclavatus from the Maestricht beds.

Coelodus [Pycnodus) subclavatus, Agass.
(PI. xlil, figs. 16-18.)

A number of teeth in the collections from Stockholm and Lund may be
relegated to this genus. The largest tooth is slightly imperfect, one extremity
being broken. The part preserved is 0*023 m. in length, and 0*007 m. in breadth ;
it is thick and massive ; surface of the crown smooth ; subclavate in outline. A
slight fold of the enamel extends round the base of the crown. Under surface
hollow and rough, for attachment to the jaw. Other specimens are smaller,
having a length of 0*017 m.

A group of five teeth (fig. 17) from the right ramus of the lower jaw exhibits
three large teeth from the inner row, and a portion of the fourth, and a smaller
one from an outer row. They are attached to a portion of the jaw having the
ordinary open, spongy texture.

Two small, round teeth, apparently belonging to the same species, have been
found in the Faxe or Coralline limestone.

Formation and Locality. — Stage Se'nonien Superieur : Kopinge. £tage Se'nonien
Inferieur : Ignaberga ; Faxe, Coralline limestone.

Ex coll. — Riksmuseum, Stockholm ; University Museum, Lund.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 417

Sub-Class. — TELEOSTEI.

Order. — Ac an thopterygii.

Family.— BERYCID^J.

Genus. Hoplopteryx, Agassiz. 1843. " Recti, sur les Poiss. Foss.,"

vol. iv., p. 131.

Body compressed, more or less oval in outline ; abdominal cavity deep ; head
large in proportion to the size of the body ; orbit large ; opercular bones serrated ;
vertebral column strong ; dorsal fin with five or six spinous rays, strong, and
widely separated. Anal fin has three spinous rays, supported by a strong
interspinous process, which reaches nearly to the vertebral column. Scales large,
strongly connected, but not coarsely punctured. Lateral line begins on the
abdominal surface, near the tail, and passes over the vertebral column forward.
It consists of arrow-shaped scales (von der Marck).

This genus is distinguished by the spinous and soft rays of the dorsal fin
being continuous without intermission ; in this respect it is separated from the
genera Holocentrum and Myripristis, in which the spinous and soft rays form two
separate fins. Agassiz* founded the genus on specimens of fish from the Chalk of
Westphalia, which he named Hoplopteryx antiquus. I have on a previous occasion
shown that some of the species associated with the genus Beryx f belong to
Hoplopteryx (B. superbus,% Ag. ; B. zippei,§ Ag. ; and B. Syriacus,\\ Pictet & H.),
and Mr. A. Smith Woodward ^[ has since adduced sufficient evidence to prove that
Beryx lewesiensis, Mantell (= B. ornatus, Agass.), should also be placed in the
genus Hoplopteryx.

Hoplopteryx lundensis, Davis.

(PI. XLIII., figs. 1-3.)

Several specimens of this species occur in the Lund Museum. The matrix is a
soft friable chalk, and the fossilized remains partake very much of the same

* " Poiss. Foss.," vol. iv., p. 131, pi. xvn., figs. 6-8.

f " Foss. Fishes of the Chalk of Mt. Lebanon," Trans. Roy. Dubl. Soc, ser. n., vol. iii., p. 513.

| "Foss. Sussex," p. 372, pi. xxxvi., fig. 5.

§ " Rech. sur les Poisson Foss.," vol. iv., p. 120, pi. xv., fig. 2.

|| " Nbuv. rech. sur les Poiss. Foss. du Mt. Liban.," p. 28, pi. i., fig. 1.

"Proc. Geol. Assoc.," vol. x., p. 327, and "Catalogue Brit. Foss. Vertebrata" ("Woodward and
Sherborn), p. 98,

418 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

character, so that where the specimens are not fragmentary, from the breaking of
the chalk, they are in few instances well preserved. The one represented on the
plate indicated above has a length from the snout to the base of the tail of
0*205 m., and the tail, which is not well represented on this or any of the other
specimens, is about an additional 0*04 m., which makes a total length of 0*245 m.
The greatest height, in front of the dorsal fin, is 0*065 m. ; thence the body
diminishes in height to the peduncle of the tail, which is about 0*025 m. in height.
The form of the body is an elongated oval, the posterior part tapering more
rapidly than the anterior.

The head has a length of 0*08 m., and the height is 0*06 m. behind the orbit.
The mouth is large, with a wide gape. The pre-maxillary (p. mx.) is 0*025 m. in
length, dilated in front, and triangular behind. It bears a large number of
small, pointed, villiform teeth, slightly larger near the anterior extremity than
those behind. The maxilla [mx.) is long, anteriorly slender, but largely expanded
towards its distal extremity. It has no teeth. The anterior extremity of the
maxilla is attached to the vomer, and in the specimen (fig. 2, vom.) the anterior
portion of this bone is shown to bear teeth. The mandible (mn.) is large and of
robust proportions; the dentary (<l) bears teeth similar to those of the pre-maxilla.
Its internal surface, exhibited by a fracture of the bone, is deeply channelled, for
the accommodation of the Meckel's cartilage ; the articular portion of the mandible
is deep, and at its lower posterior extremity is a small bone which is probably the
angular. Above this the articular portion terminates in a coronoid process,
extending upwards, at right angles to the base. The orbit (or.) is large, and
occupies a forward position above the posterior extremity of the jaws. The bones
forming the orbit, except the pre-orbital (fig. 1, p. -or.) are not well defined;
neither can the elements composing the frontal or occipital regions of the head
be very clearly distinguished. The frontal bones are shown in the specimens
represented by all the figures, and those forming the upper posterior portion of
the head in figs. 1 and 2. The arrangement of the bones composing the opercular
covering is exhibited by figs. 1 and 3. The operculum (op.) is large, with a
triangular posterior margin ; it was probably thin, and for this reason is not well-
preserved. It enveloped a portion of the body covered with scales. The sub-
operculum (s.-op.), attached to the lower extremity of the operculum, is a semi-
triangular bone, with a rounded inferior margin. The pre-operculum (p.-op.), is
best preserved in specimen fig. 3. It is a long bone, shaped like a boomerang,
with a sharp inclination forward on the anterior margin, at about one-third of its
height ; the posterior margin is finely serrated. The inter-op erculum (figs. 2 and 3,
i.-op.) is an oblong bone, the upper margin concave, whilst the inferior one is
convex ; both this and the pre-operculum are thicker and stronger bones than the
remaining components of the gill-covers. The head represented by fig. 3 exhibits

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 419

the position and sequence of the mandibulary suspensorium composed of the
hyomandibular (h), the symplectic, the quadrate, and the metapterygoid,
the latter connecting the suspensorium with the pterygoid and the ento-
pterygoid. The hyomandibular (hyo.) is largely expanded in its upper portion ;
its lower portion is contracted and partially hidden by the pre-operculum ; joined
to the hyomandibular in descending series is the symplectic or mesotympanic
(sym.), which connects with the quadrate (qu.), to which the lower jaw is attached.
The metapterygoid (nipt.) is a large, flat bone filling the space between the
hyomandibular, the symplectic, and the quadrate, and connects them with the
pterygoid {pt.) and the entopterygoid (ept.). The pterygoid is joined at its
anterior extremity to a bone, which increases in size forwards, and which is prob-
ably the palatine (pal.). Attached to this bone are numerous teeth similar to those
of the pre-m axilla. The palatine is also exhibited by the specimen represented by
fig. 2, and on this also small teeth may be distinguished. The branchiostegals
are exhibited in fig. 1. ; they are long, curved bones, tapering at the distal
extremity to a point.

The spinal column consists of thirty vertebrae, of which sixteen are caudal.
The vertebrae are large and robust, 0*007 m. in height under the anterior rays of
the dorsal fin, and 0-006 m. in length. Large haemal and neural spines, with
forked bases, are attached to the vertebrae. Connected with the haemal spines,
inter-spinous bones support the anal fin ; whilst more numerous inter-spinous bones
connect the neural spines with, and support, the dorsal fin. The ribs are long,
and of considerable strength. A short distance below the vertebral column the
ribs are crossed by a series of stylets or epiplural bones 0*015 m. in length.

The dorsal fin commences immediately over the scapular arch, and extends a
distance of 0*09 m. along the dorsal surface. It is separated from the caudal fin
by a space of 0*03 m. The anterior portion of the fin consists of a series of
spinous rays, ten in number; the sixth from the head is the largest, being 0*025 m.
in length, those before and behind diminishing gradually in size ; the most
anterior ones are short, rudimentary rays. All the rays are thick and strong,
sharply-pointed, and inclined, with a slight curvature, backwards. Eight or ten
articulated rays succeed without intermission the spinous ones ; they are longer
than the spinous rays, and divided towards the distal extremity into filaments.
The anal fin commences opposite the anterior rays of the soft part of the dorsal
fin, and extends backwards to a length of about 0*04 m., and appears to bo
separated from the base of the caudal fin by 0*03 m. ; but this part of the body is
not well preserved. The anterior rays of the anal fin, apparently three in number,
are spinous ; the posterior one is longest, equally strong and similar in form to the
spines of the dorsal fin. The anal fin spines are supported by strong inter-spinous
rays, widely expanded at the distal extremity, where attached to the fin rays.

TEAXS. HOT. DUB. SOC, N.S. VOL. IV., TAUT VI. 3 O

420 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

The articulated rays diminish in length posteriorly, and are divided by repeated
bifurcations similar to those of the dorsal fin. The caudal fin is not well
preserved in any of the specimens ; the one figured on Plate xliii. is the best.
The lower lobe consists, apparently, of eight or nine strong articulated dichotomiz-
ing rays, connected with the vertebral column by a hypural bone, but their length
cannot be determined ; the upper lobe of the tail appears to have had a similar
number of rays. The body of the fish is split down the middle, and consequently
the pectoral fins are not exhibited, but their position may be indicated by a
number of ridges showing through the scales almost midway between the dorsal
and ventral surfaces. The ventral fin is supported from the scapular arch by a
largely-expanded pubic bone. It is situated on the ventral surface, immediately
under the posterior margin of the gill-cover. The anterior ray is spinous, with a
length of 0'025 m., it is thick, and sharply-pointed. The number of fin-rays
cannot be determined, but the fins were of large size.

The scales are of medium size, the height of those situated behind the gill-
covers being 0-004 m. The posterior margin is circular, and slightly imbricated.
The surface is ornamented with striations, running more or less parallel with the
axis of the body. The direction of the lateral line (tat.) is indicated by series of
foramina, which occur on alternate scales along the superior portion of the body.

This species is readily distinguished from any previously described by the
number and position of the spinous rays of the dorsal fin, the number of vertebrae,
together with the size of the scales. The scales of Hoplopteryx zippei, Agassiz,
are not known ; those of H. syriacus, P. & H., and H. oblongus, Davis, from the
chalk of Mount Lebanon, are much larger than those of the Swedish fish ; the
scales of H. superbus, Dixon, are also large. In H. syriacus there are six spinous
rays in the dorsal fin, and its anterior ray is inserted, after a considerable interval,
behind the head. II. sippet, Ag., has five spinous rays, which are inserted
immediately behind the occiput; the number of vertebras is about two-thirds
that of the species now described. II. oblongus is possessed of six or seven dorsal
rays, and its vertebral column consists of thirty-two vertebras.

Formation and Locality — Etage Danien (zone with Anancites sulcatus, Goldf.) :
Saltholm Limestone ; Limhamn, Scania.

Ex coll. — Geological Museum, Lund University.

Hoplopteryx, sp.

(PI. xlii., figs. 19, 20.)

A number of detached scales occur in the Lund Museum from the chalk of
Limhamn. They have a transverse diameter of 0*025 m., and the length, antero-

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 421

posteriorly, is O'OlSm. The anterior margin is nearly straight, the upper and
lower margins slightly convex, whilst the posterior one is more or less crenulated.
The scales appear to have been very thin near the posterior margin, and conse-
quently easily broken. Most of the specimens are imperfect. The surface is
striated, the striations extending parallel with the upjDer and lower margin of the
scale, whilst a second series radiate from the middle of the anterior surface of the
scale, and extend to the posterior margin (fig. 19). Other scales are more or
less oval in outline, with concentric rings over the greatest portion of the surface,
the posterior part of the scale, which was uncovered by succeeding ones, being
striated (fig. 20). The greatest diameter is 0-03 m.

These scales appear to resemble most closely those of Hoplopteryx lewisiensis,
Mant. {Beryx ornatus, Ag.), and, whilst there is insufficient material to form a
species, there can be no hesitation in including them in the genus Hoplopteryx.

Formation and Locality. — Etage Danien (zone with Anancites sulcatus, Goldf.) :
Saltholm Limestone ; Limhamn, Scania.

Ex coll. — Geological Museum, Lund University.

Hoplopteryx minor, Davis.
(PI. xlv., figs. 3 and 4.)

A number of specimens of a small species of Hoplopteryx from the chalk of
Limhamn occur in the collections at the Riksmuseum at Stockholm. They are all
imperfect, and afford only a small amount of information as to their characters
and structure. The head, and a portion of the vertebral column, is all that is
preserved. The head, from the tip of the snout to the posterior margin of the
gill-cover, is 0'05 m., and the height of the head 0*04 m. The orbit was probably
large. The gill-cover consists of the pre-operculum [p. op.), a long bone, with
a crenulated margin; the operculum {op.) is imperfect, the anterior margin
slightly concave, the upper margin rounded, and the remaining part along the
posterior margin inclined to the inferior anterior extremity, so as to form an
irregular triangle. The inter-operculum is not preserved ; but a detached bone
has the appearance of being the sub-operculum (s. op.). The mandible (m.) is
attached at its posterior extremity to a triangular bone, the quadrate (q.). The
mandible is strong, deep behind, the dentary portion bearing a number of small
teeth. The maxilla (mx.) and pre-maxilla (p.-mx.) may also be distinguished,
but the dentition of the latter is not defined. Other bones may be distinguished
on the anti-orbital and inter-orbital regions of the head.

A portion of the vertebral column is preserved. It extends to a distance of

3 0 2

422 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

0-035 m. behind the occiput, and is 0'025 m. in length. The vertebrae are
0'005 m. in length, and a little less high than long.

The specimen represented by fig. 4 is in all probability a smaller example of
the same species. A number of spinous rays are preserved on the dorsal surface.
The anterior ray is located a distance behind the occiput, equal to the length of
the head. The fin-rays are supported by inter-spinous bones. The ribs are long
and moderately strong. A series of epiplural spines extend transversly to the
ribs, parallel with, but separated a short distance from, the vertebral column.

This species does not agree with any of those previously described, as far as
its imperfect remains can be deciphered.

Formation and Locality. — Etage Danien : Limhamn, Scania.

Ex coll. — Riksmuseum, Stockholm.

Genus. Berycopsis. Dixon.

This genus was proposed by Professor L. Agassiz for a fish from the Chalk of
Sussex. It has much resemblance to the genus Beryx, but differs from it in the
absence of pectinations on the free margins of the scales. The scales are of
moderate size, thick, and smooth, or only ornamented with delicate radiating
lines. The fin-rays of the dorsal and anal fins are robust. The rays of the
dorsal fin are continuous with the preceding spinous rays, six or more in number,
shorter than the soft rays, but stout and strong. Pelvic fin with a spinous ray,
and seven or more articulated rays. Anal and caudal fins unknown.

The only species known is B. elegans, Dixon, from the middle chalk, Clayton,
of which the type specimen is in the Brighton Museum. There are others in
the Natural History Department of the British Museum, South Ken sington.

Berycopsis lindstromi, Davis.

(PI. xliv., figs. 1, la.)

A large and unique specimen, which apparently belongs to this genus, occurs
in the collection of the Geological Survey at Stockholm. The length of the part
preserved is 0-23 m. ; but the fish is devoid of the caudal fin, and the head is
somewhat dislocated, and badly preserved. The body is deep, measuring 0*10 m.
in front of the dorsal fin. The dorsal and anal fins are not preserved, except the
remains of a single spinous ray of the dorsal ; but the presence of a long dorsal fin
is indicated by a long series of inter-spinous rays, which, no doubt, afforded

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 423

support to the fin. Judging from a similar analogy, the anal fin occupied a
length much shorter than the dorsal, and was situated in close proximity to the
caudal fin. The caudal fin was probably large and powerful, the bases of strong
rays surrounding the extremity of the vertebral column affording evidence to that
extent, though the fin itself is absent.

The front part of the body, with the head, is displaced, and this renders the
identification of this part of the fish obscure. The operculum on the left side has
been squeezed down, and with it the scapular bones supporting the pectoral fin.
The pectoral fin, originally occupying a lateral position, is represented on this
specimen depressed to a position on the ventral surface. It was large, and
apparently composed of a large number of rays. A second fin is represented ; it
is of considerable size, and may be the ventral fin attached to the opposite side of
the body.

The whole of the surface of the body is covered with scales ; they are thin,
closely overlapped, and of medium size ; a few scales on the ventral surface are
tolerably perfect ; the exposed part is OOOtL m. in height ; the posterior border is
circular, with a minute imbrication, determined with difficulty by a strong magni-
fier, along the margin ; the surface of the scale has a concentric arrangement of
striae, roughly parallel with the margin (fig. la). The anterior portion of the
scale is hidden beneath the posterior margins of the preceding scales. The
majority of the scales are crushed and imperfect. The vertebral column is
distinctly visible beneath the scales, especially the posterior part. It consisted of
about forty vertebras, O05 m. in length; the height slightly exceeding the length
in the median part of the body ; nearer the tail the vertebras are considerably
shorter. They are less constricted in the median part than are the vertebras of
Hoplopteryx, and the articulating surfaces are supported by numerous buttresses,
extending from one to the other. To the vertebras are attached strong hasmal
and neural spines, which in turn afford support to inter-hasmal and inter-neural
spines. These can be readily distinguished beneath the scales. The ribs are
comparatively long, reaching two-thirds the distance from the vertebrae to the
abdominal margin.

This specimen is related to Berycopsis elegans, Dixon,* from the chalk of
Sussex.

Formation and Locality. — Etage Danien (zone with Anancites sulcalus) : Saltholm
Limestone ; Linharan, Scania.

Fx coll. — Riksmuseum, Stockholm.

* " Geology and Fossils of Sussex," p. 372, pi. xxxy., fig. 8. 1850.

424 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

Family. — T RICHIURID 2E>.
Genus. Enchodus.
Enchodus, sp.

A small number of teeth, apparently belonging to the genus Enchodus, have
been found in the Upper Senonian beds characterized by the presence of Belemnites
mucronatus at Kopinge. The largest of the teeth is 0*015 m. in length, with a
diameter at the base of 0*003 m. The surface of the teeth is finely and regularly
striated longitudinally ; the tooth is compressed, and a sharp edge is produced
along each lateral margin. The teeth are broken off at the base, where they
have probably been anchylosed with the jaw. Other specimens, two-thirds the
size of the above, exhibit similar characters, one of them being especially well-
developed along the lateral margins, which extend in a knife-like process on each
side.

The teeth are probably those of Enchodus halocyon, Agassiz, (lewisiensis, Mantell)
(" Poiss. Foss.," vol. v., pt. i., p. 64, pi. xxv. c, figs. 1—16) ; but there is scarcely
sufficient preserved to satisfactorily determine the identity.

Formation and Locality. — Etage Se'nonien Superieur ; Kopinge.

Fx colt. — Riksmuseum, Stockholm.

Genus. Bathysoma. Gen. nov.

Body compressed and elevated ; head large ; snout prominent ; scapular arch
composed of bones of great length and thickness.

Bathysoma lutJceni, Davis.

(PI. xlvi., figs. 1-7.)

A fine series of specimens from the Saltholm Limestone occur in the Museum
of the University of Lund and in the Mineralogical Museum of the University of
Copenhagen. They have all been obtained from Limhamn, in Scania. The fish
is compressed laterally; it reaches a length of about 0*10 m., and the height of
the body immediately behind the scapular arch is equal to four-fifths of the
length ; or, if the measurement be taken from the anterior extremity of the
mandible to the peduncle of the tail, the height of the body is equal to the length.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 425

The head is large, and absorbs quite two-fifths of the entire length. The facial
contour forms a prominent feature. The body of the fish rapidly diminishes in size
towards the tail. It is to be regretted that no specimen is sufficiently well
preserved to exhibit the entire form of the fish ; but a more or less complete idea
can be obtained by comparing the several specimens, and taking the aggregate
result. (PI. xlvi., fig. 7.)

The head is produced anteriorly, and terminates in a protruding snout ; the pos-
terior margin, formed by the operculum and a thin median bone extending from the
supra-occipital region forwards, is more or less circular in outline. The orbit is
situated in the posterior moiety of the head, and is somewhat high; it is large
and encircled by bones. In front of the orbit a large but thin bone may be
distinguished, which represents the pre-orbital ; its posterior boundary is formed
by the margin of the pre-operculum. A straight bone, probably the para-sphenoid,
extends across the base of the orbit. The maxilla is long and somewhat slender,
and is divided by an oblique suture from the pre-maxillary. The mandible
is large, high in front, diminishing in size backwards, and extending to a
position beneath the orbit, where it is articulated with the quadrate. No teeth
can be distinguished on any of the specimens, either on the upper or lower jaws.
The inter- orbital bones are not well preserved on any of the examples ; but
fragmentary outlines exist which indicate that the frontal and occipital bones are
produced, and form a thin median bony crest, extending above the orbit back-
wards. The operculum consists of four elements : the pre-operculum is a
triangular bone, with a concave anterior margin, pointed above, and rounded
below ; deep ridges extend from the pointed upper margin, and radiate towards
the circular inferior margin. Behind and above the pre-operculum is the
operculum ; it is rounded behind, and channels radiate over its surface from the
upper anterior margin, where it joins to the pre-operculum. It is the largest of
the opercular bones. The sub- operculum is a long bone, extending parallel with
the operculum, and situated immediately behind it. The inter-operculum is also
long and narrow, extending from the sub-operculum to the anterior extremity of
the pre-operculum. Other bones of the head may be distinguished, but not with
sufficient distinctness to be readily identified.

The vertebral column consists of thirty vertebrae, of which ten are abdominal,
and the remainder caudal. The vertebras nearest the head are equal in height to
the length, but towards the tail they become gradually narrower? so that the
height is greater than the length. The centra are biconcave, and the median
external surface is much constricted. The apophyses of the vertebrae are strong
and afford attachment to haemal and neural spines, the former of great length.
The upper part of the body is not in any instance well preserved ; but the neural
spines are seen to have an elevation of 0'02 m., and the fragmentary remains of

42G Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

inter-neural spines are present. The haemal spines are longer than the neural.
Attached to them are inter-haemal bones of great strength ; their anterior and
posterior margins are expanded, so that the series form an almost continuous bony
mass. The anterior inter-haemal bones are more numerous than the haemal
spines. There are two, and in the anterior part three, inter-haemals to one
haemal. The first haemal and inter-haemal are very thick and strong, and are
each of so great a length that they overlap to a considerable extent. The lower
extremity of the inter-haemal is widely expanded, and with a convex curvature
extends forward to such an extent as to form an attachment with the styliform
process of the post-clavicle and other elements of the scapular arch. With so
strong a basis for support, it will naturally be inferred that the anal fin was
large, with anterior spinous rays, but no trace of the actual fin remains on the
specimens under examination. Nearer the caudal fin both the haemal and neural
spines and their auxiliaries become rapidly smaller. The caudal fin is attached by
a short peduncle ; the terminal vertebra supports an expanded triangular hypural
bone, to which the rays of the tail are attached. Like the dorsal and anal fins,
the caudal is not well preserved ; but one specimen shows that the caudal was
composed of numerous finely-articulated fin-rays. The ribs were short and
attenuated.

The scapular arch exhibits a peculiar modification, adapting it to the great
depth of the body. The upper members of the series are hidden by the overlying
bones of the operculum. Immediately behind the extremity of the mandible, the
clavicle extends with a gentle curvature backwards and downwards, and at its
extremity joins a styliform process of the coracoid. Attached to these bones is
the pubic, a large bone, widely expanded at the base, but tapering upwards to a
pointed extremity. The clavicle is a strong bone, with an expansion of the upper
surface. A very long and slender post-clavicle, its attachment at the upper end
hidden by the gill-covers, descends in the form of a styliform process, and assists
in giving support to the large pubic bone, to which the ventral fin was doubtless
attached, but nothing remains to indicate its size or form.

Amongst existing fishes the Sun-fish, Lampris luna, is a pelagic fish, which
attains to a great size ; it is found commonly near Madeira, and from thence
northwards in the Atlantic. Its skeleton exhibits a very large development of the
scapular arch, and in many respects it closely resembles the fossil. The clavicle
is very long and dilated, and the post-clavicle, slightly expanded at the top,
descends in the form of a long styliform bone. Similar characters, but less
distinctly specialized, may be observed in the skeleton of Capros aper, a Mediter-
ranean fish, sometimes found on the coasts of England.

Some of the species of the fossil Gastronemus, most especially G. rhombeus, Ag.,*

* "Poissous Fossiles," vol. v., p. 20, pi. n., figs. 1, 2.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 427

present some features of great similarity to the species now described. The body
is elevated and compressed ; the scapular arch large and well developed ; ribs
small and insignificant, and the inter-spinous bones large and expanded. The
vertebral column is more massive and stronger in proportion to the size of the fish ;
it is composed of twenty-four vertebrae, whilst in the species now described there
are thirty. Gastronemus occupies a position intermediate between the forms
represented by Vomer* and the species now described, with a strong inclination
towards Vomer. Both these genera have the same number and distribution of
the vertebras ; but in this species the vertebral column is smaller and less
robust, whilst the number of its constituents is larger. The pectoral fin is large
in Vomer and Gastronemus, but in this genus is comparatively small. The
greatest and most characteristic divergence will be found, however, in the
character and composition of the elements of the scapular arch.

Formation and Locality. — Saltholm Limestone ; Etage Danien (zone with
Anancites snlcatus, Goldf.) : Limhamn, Scania.

Ex coll. — University Mineralogical Museum, Copenhagen ; University Geo-
logical Museum, Lund.

Order.— PHYSOSTOMI.

Family. — CLUPEID 2E>.

Genus. Clupea. Linn.

Body compressed, with the abdomen serrated, the serrature extending forwards
to the thorax. Scales of moderate or large, rarely of small, size ; upper jaw not
projecting beyond the lower; cleft of the mouth of moderate width; teeth, if
present, rudimentary and deciduous. Anal fin of moderate extent, with less than
thirty rays ; dorsal fin opposite to the ventrals ; caudal forked.

Clupea hmdgreni, Davis.
(PI. xlv., fig. 5.)

A unique specimen of this genus occurs in the Museum of the University of
Lund. It is unfortunately imperfect. The part of the body preserved includes

* "Poissons Toss.," vol. v., p. 28, pis. v. and vn.

TRA.NS. EOT. DUB . SOC, N.S. VOL. IV., PART VI.

3 P

428 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

the base of the caudal fin, the anal fin, a portion of the dorsal fin, and about forty
vertebrae, of which sixteen are caudal. The length of the spinal column, which
is preserved, is O09m., and the total length of the fish, as indicated by this
portion, was probably 0*15 m. The vertebrae are as high as broad, bi-concave,
and much constricted medially. Each vertebra supports a haemal and neural
spine, long and slender, and as nearly as possible equal in length. Portions of the
anal fin are preserved, but not sufficient to by so indicate precisely its form and size.
The dorsal fin is represented by twelve fin-rays; the posterior rays are O05 m. in
advance of the caudal fin. Opposite the anterior rays of the dorsal fin the ribs
commence. They are strong and a considerable length. The tail is imperfect,
only the base being preserved. No scales can be identified.

Formation and Locality. — Etage Danien : Saltholm Limestone ; Limhamn.
Ex coll. — University Geological Museum, Lund.

Family. — HOPLOPLEURID2E, Pictet.
" Traite* de Paldontologie," 2nd ed., vol. ii., p. 213.

" Body generally with four series of sub-angular scutes, and with intermediate
scale-like smaller ones. One (?) dorsal only ; head long, with jaws produced."

The family Hoplopleuridae was established by Pictet for fishes which were
devoid of scales properly so-called, but which are protected on the back and sides
by rows of scutes. The head is long and the jaws provided with pointed teeth of
unequal size. The bones of the head are frequently sculptured or granulose.
The genera associated in this family by M. Pictet are Dercetis, Agassiz ; *
Sauroramphus, Heckel;f Eurypholis, Pictet; % Pelargorhynchus, Von der
Marck ; § Leptotrachelus, Von der Marck ; || Plintrophorus, Giinther.^ The
fishes included in the genus Dercetis were considered by Agassiz to resemble the
sturgeons in the arrangement of the dermal scutes, and were grouped amongst the
Ganoids. Heckel held the same opinion with respect to the position of Sauro-

* " Poisson Fossiles." vol. ii., pt. ii., p. 258. 1843.

t "Bcitr. zur Kermt. der. Foss. Fische Osterreichs," p. 17. 1849.

I " Desc. Poiss. Foss. du Mt. Liban.," p. 28. 1850.

§ " Ueber einige Wirbelthiere, &c, der Westphalischen Kreide." — Zeitschr. deutsch. Geol. Ges., vol. x.,
p. 242. 1858.

|| " Fossile Fische, Krebse und Pflanzen aus dem Plattenkalk der jiingsten Kreide in "Westphalen."
— Palteontographica, vol. ix., p. 61, pis. xi., xii., fig. 3. 1863.

^ " Desc. of a New Foss. Fish from the Chalk."— Geol. Mag., vol. i., p. 114, pi. vi. 1864.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 429

raniphus, and Von der Marck also places the genera Pelargorhynchus and
Leptotrachelus amongst the Ganoids, but regards Ischyrocephalus as a
Teleostean. A careful review of the whole of these genera, assisted by additional
specimens of Leptotrachelus and Eurypholis discovered in the chalk of Mount
Lebanon, convinced M. Pictet that they formed a group naturally associated,
especially by the great analogy afforded by the peculiar arrangement of the
series of scutes, and that they formed a family of the Teleosteans, to which he
gave the above name.

Genus. Dercetis. Agassiz, " Rech. sur les Poissons Fossiles," vol. ii., pt. ii.,
p. 258, pi. Lxvi.a, figs. 1, 2, 5, 6, 7, 8 (non figs. 3, 4).

Syn. — Leptotrachelus, . . V. de Maeck, 1863-64. " Fossile Fische, Krebse

und Pflanzen aus dem Plattenkalk der jiing-
sten Kreide in Westphalen." — Palgeonto-
graphica, vol. xi., p. 59.
Leptotrachelus, . . Pictet et Humbeet, 1866. " Nouv. Eech s. les

Poissons Fossiles du Mount Liban.," p. 93.
Leptotrachelus, . . Davis, 1887. " On the Fossil Fishes of the

Chalk of Mt. Lebanon."— Trans. Roy. Dub.
Soc, ser. ii., vol. iii., p. 619.

The genus Dercetis was instituted by M. Agassiz, in concert with Count
Minister, for fossil fishes, with elongated body and head, the latter prolonged into
a straight beak. The upper jaw a little longer than the lower, both being armed
with elevated conical teeth, alternating with others smaller. The spinal column
composed of robust vertebras, longer than high, and constricted in the middle.
Pectoral fins large, the ventrals small and composed of few rays. The dorsal fin
is described as extending along nearly the whole surface of the back, the anal
being about half the length of the dorsal, and finishing at the same point. The
caudal short and slightly forked. The sides of the body are furnished with three
rows of scutes, extending the whole length, and resembling those of the sturgeon.
The scutes are heart-shaped, osseous, with a granular external surface, and
surmounted by an angular median projection. The species described as pertain-
ing to this genus are D. elongatus, Ag., from the chalk of Lewes, England, and
D. scutatus, Miinst. and Ag., from the Chalk of Westphalia. Mr. A Smith Wood-
ward * has already pointed out that the English specimens are entirely devoid of
fins ; and it may consequently be presumed that the description of the long dorsal
and anal fins was taken from the Westphalian species. It may further be inferred,

* " Proc. Geol. Assoc.," vol. x., p. 318. 1888.

430 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

that such being the case, the specimens were identical with those found in the
same strata, which have since been described by W. Von der Marck under the
generic name of Pelargorhynchus, which possesses a very long dorsal fin, and an
anal similar to the one described by Agassiz.

In 1850, F. J. Pictet described three species of Dercetis from the Chalk of
Mount Lebanon. Two of these, namely, D. triqueter and D. tenuis, were subse-
quently transferred in the " Nouvelles Recherches sur les Poissons Fossiles du
Mont. Liban." (1866), to the genus Leptotrachelus, Von der Marck ; and the addition
of specimens in a better state of preservation proved that the D. tenuis was derived
from the cervical region of D. triqueter. The third species Dercetis linguifer,
Pictet, known only from a fragment of the body, very imperfectly preserved,
was still doubtfully retained as representing the genus Dercetis in the Chalk of
Lebanon.

In the description of the fossil fishes of Mount Lebanon* published in 1887,
it is remarked that since the year 1866 a considerable number of specimens of
Leptotrachelus have been obtained, and these differ much in size as well as in the
details of the form of the scutes ; and there can be no doubt that the figure given by
M. Pictet {op. cit., pi. ix., figs. 7, 8) is that of a portion of the body of a large fish
of the genus Leptotrachelus, and that it is the same species as those already
included in the species L. triqueter, Pictet and Humbert. Since the above was
written I have had opportunities of examining the originals, in the Mantell
collection at the British Museum (Natural History Department), figured by
Professor Agassiz, and I am convinced that they are the same genus as the fish-
remains described as Leptotrachelus from Mount Lebanon. t This being so, it
becomes a question of synonomy, and as Dercetis was established about twenty
years before Leptotrachelus, it follows that the latter must be considered as a
synonym of Dercetis, Agass. The Lebanon fish-remains included under Lepto-
trachelus triqueter, Pictet and Humbert, will revert to the original designation of
Pictet, and be again Dercetis triqueter (including D. tenuis, Pictet, and D. linguifer,
Pictet), and the species Leptotrachelus hakelensis,% Pictet and Humbert, and
L. gracilis, § Davis, will be Dercetis hakelensis and D. gracilis.

Dr. Anton Fritsch describes specimens from the chalk of Wehlowitzer Planer,
near Prague, which he has named Dercetis reussii,\\ Fritsch. The remains are

* " Trans. Hoy. Dublin Soc," ser. n., vol. iii., p. 619.

f See A. Smith Woodward "On Fossils of the English Chalk." — Proc. Geol. Assoc., vol. x., p. 319.
1888.

+ " Nouv. Rech. s. lcs Poiss. Foss. du. Mt. Liban.," p. 98, pi. xiv., fig. 3. 1866.
§ "Trans. Roy. Dublin Soc," ser. n., vol. iii., p. 623, pi. xxxvnr., fig. 3. 1887.
|| " Die Reptilien und Fische der Bohraischcn Kreideformation," p. 20, pi. n., fig. 8 ; pi. iv., fig. 1 ;
pi. .v., figs. 1, 6. 1878.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 431

fragmentary, consisting of the head and portions of the vertebrae, imperfectly
preserved. They do not present sufficiently characteristic features for full
comparison with the species already, or presently to be, described.

For the opportunity of studying the specimens which I now proceed to describe
I am indebted to the courtesy and kindness of Dr. W. Dames of Berlin, to whom
Dr. Lundgren had entrusted them, along with others, for description, previously
to my visit to the Lund Museum. In order to render this memoir as complete as
possible, Dr. Dames readily consented to place the fish-remains at my disposal,
retaining the bird-remains which form the new genus Scaniornis, Dames.*

Dercetis limhamnensis, Davis.
(PI. xlv., figs. 1, 2.)

Portions of this fish of large size have been found in the Faxe Chalk. The
matrix is so soft and friable that the specimens, being of the same character, are
not well preserved. The head and a part of the vertebral column is preserved,
and parallel with the vertebrae are a number of scutes. The entire length of the
head, from the snout to the posterior margin of the operculum, was probably
0-10 m. This portion of the body is succeeded by eighteen vertebrae, which
occupy a length of 0.10 m. Compared with other species of the same genus, the
parts preserved appear to indicate a fish having a total length of about a metre.
There is no evidence of fins preserved.

The head is divided on the matrix from side to side in a plane parallel with
the crown. The bones were thick and massive, but are so fractured that it is
almost impossible to identify them. The position of the orbits, owing to the
manner in which the head is divided, cannot be determined with certainty, but
the depression at the side of the head may indicate its position (fig. 1.,
or fig. 2). The operculi have entirely disappeared. The bones of the
cranium were thick and strong, and an impression remains on fig. 2 which
exhibits the form of the occipital part of the skull.

The mandibles are articulated at a point quite under the posterior extremity of
the skull, their length being 0'06m. The dentary bone occupies a little more
than half the length. A number of small setiform teeth, with acuminate apices,
cover the upturned alveolar surface of the left mandible. Other strong bones
running parallel to the mandibles may indicate the maxillae ; but if so, they are
not sufficiently distinct to allow of description. A strong sigmoidally-curved bone,

* " Ueber Vogelrestc aus dem Saltholraskalk von Limhanm bei Malmo." — Bihang till k. Svenska
Yet.-Akad. Handlingar, Band 16, afd. iv., No. 1.

432 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

O035 m. in length, extends between the occipital and the anterior vertebrae, and
represents the scapular bones (sc.). The operculum probably occupied this area,
but has entirely disappeared, unless the fine bone (op.) be a transverse section
of it.

The spinal column is represented by eighteen vertebras. A space between the
head and the first vertebra preserved forms an interval requiring six or seven
vertebrae to fill it. The vertebra} are 0'005 m. in length and 0*006 m. in height,
in this respect differing much from those of Derectis (Leptotrachelus) triqueter,
Pict. & Humb., from Mount Lebanon, in which the vertebrae near the head are
twice as long as high. The vertebrae are constricted in the middle, and well
ossified. (PI. xlv., fig. 1 c.)

The scutes have, at least, two forms ; one represented by fig. 1 a is probably
from the median lateral line ; the front consists of a pointed prolongation of the
median axis ; on each side are aliform expansions of the surface, whilst the
posterior margin is made up of a pair of projections, one on each side the median
line of the scute. The pointed prolongation of this scute may have been
perforated by the canal of the lateral line. Mr. A. Smith Woodward has figured
an example of a scute of Dercetis elongatus, Agass.,* from a flint-nodule found in
the Chalk of Norfolk, England, which exhibits this peculiarity very beautifully.
A second form on the specimen from Limhamn is represented by fig. 1 b, and is
from the dorsal surface ; it varies considerably from the lateral scute, and, so far
as can be observed, extends from the median dorsal line, with the point towards
the lateral line, a corresponding scute opposing it, and extending in the opposite
direction. The two series of opposing scutes in the example figured may be seen
to some extent enveloping the vertebral column, and extending from it on each
side, with the point outwards.

The form and character of the scutes, together with the vertebrae, separate this
species from those previously described, and I indicate it specifically by the name
of the district from which it was obtained.

Formation and Localities. — Etage Danien : Saltholm Limestone : Limhamn, near
Malmo, in Schonen.

Ex coll. — Lund University Geological Museum.

* " Proc. Geol. Association," vol. x., p. 318, pi. i., fig. 7.

Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 433

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NAME OF SPECIES.

Myliobatis, sp. (?)

Ptychodus decurrens, Agass., .

,, mammillaris, Agass.,
Notidanus microdon, Agass., .

,, dentatus, A. S. W.,
Scyllium planum, Davis,
Scapanorhynchus tenuis, Davis,
,, latus, Davis,
,, gracilis, Davis, .
Odontaspis acuta, Davis,

,, acutissima, Agass.,

,, faxensis, Davis, .

,, kopingensis, Davis,
Oxyrhina mantelli, Agass.,

,, lundgreni, Davis, .

,, zippei, Agass.,

,, conica, Davis,
Lamna elegans, Agass., ....
,, incurva, Davis, ....

434 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia.

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NAME OF SPECIES.

Otodus appendiculatus, Davis,

,, limhamnensis, Davis, .

,, obliquus, Agass.,
Carcbarodon rondeletti, M. & H., .
Corax lindstromi, Davis,
Iscbyodus brevirostris, Newton,
Ccelodus subclavatus, Agass.,
Hoplopteryx lundensis, Davis,

sp. (?), ....
,, minor, Davis,
Berycopsis lindstromi, Davis,
Batbysoma lutkeni, Davis,

Encbodus, sp.,

Clupea lundgreni, Davis,
Dercetis lirahamnensis, Davis,

PLATE XXXVIII.

FOSSIL FISH OF THE CEETACEOUS FORMATIONS OF SCANDINAVIA.

TRANS. EOT. DUB. SOC, N S. VOL. IV., PART VI.

EXPLANATION OF PLATE XXXVIII.

Figure

1, 2. Ptyehodus decurrens, Agass.

1. Annetorp. Ex coll. — Riksinuseuin, Stockholm.

2. Oretorp. Ex coll. — ,,

3. Ptyehodus mammillaris, Agass. 3 a. Side view.

Annetorp. Ex coll. — Riksmuseum, Stockholm.

4-7. Notidanus microdon, Agass.

4, 5. Teeth of the upper jaw. 4«. Enlarged.
6,7. Teeth from lower jaw. 6 a. Enlarged.
4, 5, 6. Malmstrtim. Ex coll. — Geological Museum, University, Lund.
7. Limhamn. Ex coll. — Riksmuseum, Stockholm.

8. Notidanus dentatus, Smith Woodw.

Faxe. Ex coll. — Zoological Museum, University, Copenhagen.

9. Scy Ilium planum, Davis, -f-.

Terkild-Skov. Ex coll. — Mineralogical Museum, University, Copenhagen.

10-13. Scapanorhynchus tenuis, Davis.

10. Tooth ; a. internal surface, enlarged f ; b. side view.

1 1 . Median tooth ; a. internal surface, enlarged f .

12. Posterior tooth, natural size.

Oretorp. Ex coll. — Riksmuseum, Stockholm.

14-17. Scapanorhynchus latus, Davis.

14. Anterior tooth ; a. external surface ; b. side view ; c. internal surface.
Enlarged -f- .
15, 16, 17. Other specimens.

Oretorp. Ex coll. — Riksmuseum, Stockholm.

18-20. Scapanorhynchus gracilis, Davis.

18rt. Internal surface ; b. side view ; c. external surface. Natural size.
Annetorp. Ex coll. — Geological Museum, University, Lund.

21-24. Odontaspis acuta, Davis. (All natural size.)

21. a. External surface ; b. side view ; c. Internal surface.

23. a. External surface ; b. side view.

21. Annetorp. Ex coll. — Geological Museum, University, Lund.

22. Oppmanna. Ex coll.— ,, ,, ,, ,,

23. Stevns. Ex coll. — Mineralogical Museum, University, Copenhagen.

24. Faxe. Ex coll. — ,, ,, ,, ,,

25. Odontaspis acutissima, Agass.

Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen.

26. Odontaspis faxensis, Davis.

a. External surface ; b. side view ; c. internal surface.

Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen.

27, 28. Odontaspis kopingensis, Davis.

a. External surface ; b. side view ; c. internal surface.

27. Kopingc. Ex coll. — Mineralogical Museum, University, Copenhagen.

28. Saltholm. Ex coll. — Riksmuseum, Stockholm.

[2]

Trans. R.Du b. S.,~N. S., Vol.. IV.

Plate XXXVIII.

T.W.Davis, dir. V.' II Crowther, del.

WfstpNewman. imp

PLATE XXXIX.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAVIA.

EXPLANATION OE PLATE XXXIX.

Figure.

1-7. Oxyrhina mantelli, Agass.

1. a. External surface of a median tooth ; b. side view ; c. internal surface.
1-5. Oppmanna. Ex coll. — Geological Museum, University, Lund.
6, 7. Linihamn. Ex coll. — Riksmuseum, Stockholm.

8-13. OxyrMna lundgreni, Davis.

8. Anterior tooth, external surface.

9. Anterior tooth, with the root attached, external surface.

10. Highly-curved example, external face ; a. side view.

11. a. External surface ; b. side view ; c. internal surface.

8. Linihamn, Skanie. Ex coll. — Riksmuseum, Stockholm.

9. Eaxe. Ex coll. — Mineralogical Museum, University, Copenhagen.
10, 13. Oppmanna. Ex coll. — Geological Museum, University, Lund.

11. Linihamn. Ex coll. — Riksmuseum, Stockholm.
1 9

1 n ii ii ii

14. Vertebra of Oxyrhina, sp.

14 a. Side view of the same specimen.

Tra i is. R.Dub. S.,Ti S.,Vol. IV.

Plate XXXIX.

T. W. By vis. dir. '.VH Crowdier, del

West, Newman imp.

PLATE XL.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAVIA.

[SI

EXPLANATION OF PLATE XL.

Figure.

1-7. Oxyrhina zippei, Agass.

la. External surface ; b. side view ; c. internal surface.
1-4. Oppmanna. Ex coll. — Geological Museum, University, Lund.
5-7. Oretorp. Ex coll. — Riksmuseum, Stockholm.

8, 9, 10. Oxyrhina conica, Davis, sp. nov.

8a. External surface ; b. side view ; c. internal surface. All x 3 diameters.
9. Posterior tooth.

10. Median tooth.

Oretorp. Ex coll. — Riksmuseum, Stockholm.

11-17. Lamna eleyans, Agass.

11. Anterior tooth ; a. external surface ; b. internal surface.

12. Side view of anterior tooth.

13a. External surface ; b. internal surface. With lateral denticles.
14. External surface, with lateral denticle of median tooth.
15, 16. Posterior teeth.

17a. External surface ; b. side view ; c. internal surface.

Oppmanna. Ex coll. — Geological Museum, University, Lund.

18-24. Lamna incurva, Davis.

18a. External surface ; b. side view ; c. internal surface.
19, 20, 22. External surface.
21, 23. Internal surface.

24a. External surface ; b. side view ; c. internal surface.
18-23. Oppmanna. Ex coll. — Geological Museum, University, Lund.
24. Annetorp. Ex coll. — ,, ,, ,, ,,

25. Vertebra of Otodus, transverse section.
2fi

Faxe Limestone. Ex coll. — Geological Museum, University, Lund.

27. Vertebra of Otodus, sp.

a. Concave surface of centrum ; b. lateral surface.
Ignaberga. Ex coll. — Geological Museum, University, Lund.

28-32. Series of Small Vertebrae.

a. Centrum Enlarged ; b. lateral views enlarged.
Kopinge. Ex coll. — Riksmuseum, Stockholm.

33. Coprolite of Otodus.

Kopinge. Ex coll. — Riksmuseum, Stockholm.

[61

Trans. R.l)ub. S„N.S., Vol. IV.

Plato XI..

T W Davis, dir W,H. Crowthor. del.

West , Newman, imp

PLATE XLI.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAYIA.

[7]

EXPLANATION OF PLATE XLI.

Figure.

1—11. Otodus appendiculatus, Agass.

1. Anterior tooth ; a. external surface ; b. side view ; c. internal surface.

2-6. Common forms of the teeth.

7, 8. Median teeth.

9-11. Posterior teeth.

1. Oppmanna. Ex coll. — Geological Museum, University, Lund.

2, 3, 4, 5. Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen,

6. Faxe. Ex coll. — Zoological Museum, University, Copenhagen.

7, 8, 9. Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen.

10. Annetorp. Ex coll. — Geological Museum, University, Lund.

11. Saltholm. Ex coll. — Collection of King Christian VIII., Copenhagen.

12. Otodus limhamnensis, Davis.

la. External; b. internal surface ; c. side view.

Limhamn, Scania. Ex coll. — Puksmuseum, Stockholm.

13. Otodus obltquus, Agass.

13a. External surf ace ; b. internal surface ; c. side view.

Eugaard v. Grenaa, Steenberg. Ex coll. — Zoological Museum, University,
Copenhagen.

14. Carcliarodon rondeletti, Mull, and Henle. .

Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen.

[8J

TW. Davis, dir. WH Crowtlier, del

Wetit.-NewiiiAiri, imp

PLATE XLII.

FOSSIL FISH OF THE CEETACEOIJS FORMATIONS OF SCANDINAVIA.

TRANS. ROY. DUB. SOC, N.S. VOL. IT., PART. VI.

EXPLANATION OF PLATE XLII.

Figure.

1 . Section of Vertebra of Otodus, sp.

Eaxe. Ex coll. — Zoological Museum, University, Copenhagen.

3-11. Corax lindstromi, Davis, a. External surface ; b. internal surface.

3, 4. Oppmanna. Ex coll. — Geological Museum, University, Lund.
5-11. Ignaberga. Ex coll. — ,, ,, ,, ,,

12, 13. Ischjodus brevirostris, Newton.

12. Oppmanna. Ex coll. — Geological Museum, University, Lund.

13. Kopinge. Ex coll. — ,, ,, ,, ,,

14. Ischjodus brevirostris, Newton. Left pre-maxilla.

Ignaberga. Ex coll. — Geological Museum, University, Lund.

15. Ischjodus brevirostris, Newton. Mandible.

Ifo. Ex coll. — Geological Museum, University, Lund.

16-18. Ccehdus subclavatus, Ag.

16, 18. Ex coll. — Piksmuseuni, Stockholm.

17. Ignaberga. Ex coll. — Geological Museum, University, Lund.

19, 20. Hoplopteryx, sp.

Limhamn. Ex coll. — Geological Museum, University, Lund.

21. Vertebra of Otodus.

Faxe. Ex coll. — Mineralogical Museum, University, Copenhagen.

[10]

Trans. RJ)ub.S.,N.S.,Vol.IV.

Plate XLII.

PLATE XLIII.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAVIA.

[11]

EXPLANATION OF PLATE NLI1I.

Figure.

1-3. Hoploptcryx lundensis, Davis.

Or. orbit, p. or. pre-orbital, p. sph. paraspbenoid, pt. pterygoid, e. pi. entopterygoid,
hyo. byornandibular. mpt. nietapterygoid, sym. symplectic, quad, quadrate,
op. operculum, p. op. pre-operculum, s. op. sub-operculum, i. op. inter-
opereulum, mx. maxilla, p. mx. pre-maxilla, m. mandible, dent, dentary,
vom. vomer, tur. turbinal, fir. frontal.

Limhamn. Ex coll. — Geological Museum, University, Lund.

[12 |

PLATE XLIV.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAVIA.

EXPLANATION OP PLATE XLIV.

Figure.

1. Berycopsis lindstromi, Davis.

la. Scale from the ventral surface enlarged.
Ex coll. — Eiksmuseum, Stockholm.

14]

PLATE XLV.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAYIA.

[15]

EXPLANAEION OF PLATE XLV.

Figure.

1 . Dercetis limhamnensis, Davis.

la. Lateral scute enlarged two diameters.

15. Scute from dorsal surface, enlarged two diameters.
Ic. Vertebrae enlarged.

2. Dercetis limhamnensis, Davis. Head of the same specimen, exhibiting the occipital arrange-

ment of head-bones.

Limhamn. Ex coll. — Geological Museum, University, Lund.

3, 4. Hoplopteryx minor, Davis.

Limhamn. Ex coll. — Biksnruseum, Stockholm.

5. Clupea lundgreni, Davis.

Limhamn. Ex coll. — Geological Museum, University, Lund.

[16]

PLATE XLVI.

FOSSIL FISH OF THE CRETACEOUS FORMATIONS OF SCANDINAVIA.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART VI.

EXPLANATION OF PLATE XLVI.

Figure.

1, 2. Bathysoma lutkeni, Davis.

Limhamn. Ex coll. — Mineralogical Museum, University, Copenhagen

3, 4. Bathysoma lutkeni, Davis.

Limhamn. Ex coll. — Geological Museum, University, Lund.

5. Bathysoma lutkeni, Davis. Vertebrae and haemal spines of a larger example.

6. ,, ,, ,, Anterior one of the same, enlarged.

Limhamn. Ex coll. — Geological Museum, University, Lund.

7. Bathysoma lutkeni, Davis. Eestored.

Or. orbit, op. operculum, p. op. pre-operculum, s. op. sub-operculum, i. op. inter-
operculum, mx. maxilla, p. mx. pre-maxilla, m. mandible, sup. oc. supra-
occipital, cl. clavicle, cor. coracoid, scap. scapula, p. cl. post-clavicle,
puo. pubic.

[18|

Tr aus . Kbuh. sjn . s yoi.iv:

Plat e XLVI.

J W.Davis dir WHCrowtier del.

West. Newman ijrcp

n

[ 435 ]

VII.

STIEVEY OF FISHING GEOUNDS, WEST COAST OF IEELAND, 1890. I.— ON THE
EGGS AND LAEViE OF TELEOSTEANS. By EENEST W. L. HOLT, St. Andrew's
Marine Laboratory. Plates XLYII. to LIL, and Table.

[Read November 19, 1890.]

[communicated by professor a. C. HADDON, M.A.]

These Notes comprise a series of Observations on Teleostean ova (and larvae
hatched therefrom, on board) collected off the west coast of Ireland, between Aran
Islands on the south and Killybegs Bay on the north, during the cruise of the
"Fingal" on the Royal Dublin Society's Survey of Fishing Grounds between
the 12th of June and the 11th of July, 1890.

All observations and drawings of the living forms were, of necessity, made on
board, and it may be urged, as an excuse for their incompleteness, that a ship,
even in fine weather, of which we experienced little, is not the best place for
microscopical study, whilst it was only possible to devote to this subject such time
as could be spared from the more important duties (in view of the objects of the
expedition) of examining the reproductive organs and food of the adult fishes, in
addition to faunistic observations and preservation of specimens of special interest.
A few further notes on the egg-capsule have been made at this laboratory from
specimens brought from Ireland.

The methods used for the capture of pelagic ova were (1) towing at the
surface small ring-nets of fine cheese-cloth at the sides of the vessel whilst trawling;
(2) sinking larger ring-nets and a large triangular midwater-net, after Professor
M'Intosh's pattern, to a fathom or so below the surface, and allowing the ship to
drift with them for a short time ; (3) sinking ring-nets to various depths whilst at
anchor in a tide-way ; (4) trawling from the ship's boats with a small naturalist's
trawl with muslin net; owing, probably, to some defect in the latter, this method
was not very successful. The first method proved by far the most productive, and
is convenient, as it can be carried on whilst the ship is trawling. It has one
drawback — that one is apt to capture in the net many things not essentially

TRANS. EOT. DDB. SOC, N.S. VOL. IV., PART VII. 3 Q

436

Holt — On the Eggs and Larvce of Teleosteans.

marine. The second method yields fair results, but necessitates a certain
expenditure of time. It also appeared that ova were more abundant at the
surface than a short distance below, on the comparatively fine days when this
method was adopted. The third method was successful on one occasion in
Blacksod Bay on the flood tide, the ova occurring in the surface-net.

Young fish, principally mackerel-midges (Motella) and suckers (Liparis), occurred
often in the surface-nets, the latter always amongst drift weed, under which the
former also appeared frequently to take shelter. Many other young fish were
obtained with the naturalist's trawl with shrimp mesh, but these do not enter into
the subject of this Report.

The ova were separated from the rest of the contents of the net by examination
in glass tubes at sea, and were sorted, when at anchor, and the different species
placed in separate vessels — individuals being further isolated when occasion
required. The vessels used were shallow circular jars, or, failing a sufficient
number of these, short tubes of 2\ inches by \\ inch. Accidents were frequent
in bad weather, till the vessels were placed in a large zinc tray on a swinging
table in the saloon, where they were comparatively safe from upsetting, but
open to the attacks of dust. A good supply of water was usually brought in
from the open sea, but it was found that frequent changes of water were not
beneficial.

In the case of several species only one or two individuals were obtained, which
were kept alive as long as possible for observation, and, having finally died, were
of little or no service for further investigation.

My best thanks are due to the Director of the expedition, the Rev. W.
Spotswood Green, one of H. M. Inspectors of Fisheries, Ireland, for his unvarying
kindness in assisting me to obtain specimens ; and I have also to thank Mr. T. E.
Duerden, of the Royal College of Science, for help in sorting the ova obtained.
To Professor Haddon I am also indebted for much help in various ways. Pro-
fessor M'Intosh, f.r.s., has allowed me to draw up this Report at this laboratory,
and has enabled me, by advice and criticism, to add considerably to its value.

A number of pelagic ova were obtained which cannot be definitely referred to
any species. I have, accordingly, placed tliem in a series of Roman numerals —
I. to IX.

In the arrangement of the known forms I have followed Giinther's classification.
The unidentified species have no special arrangement.

My figures are not drawn to a uniform scale. I have, therefore, appended a
Table to show the relative sizes of the different ova. The actual dimensions of
the young fish are shown in the usual manner in the plates.

Holt — On the Eggs and Larvce of Teleosieans.

437

ScOMBKIDjE.

Scomber scomber (Linn). The Mackerel.

About fifty small autumn mackerel, from the neighbourhood of Broadhaven
Bay, were examined by Mr. Duerden and myself on the 20th June. We found that
many of the males were ripe, whilst the females were, in various stages, approach-
ing ripeness, with the exception of one which was fully ripe.

Day* remarks, on the authority of Dunne, that this species spawns at Meva-
gissey in May or June ; and Cunningham f gives June and the first half of July
for the Plymouth district. The period seems to extend to August in Scotch waters.^
Sars found that spawning usually took place in the first half of July.

Teachinid^e.
Trachinus vipera (Linn.) The Lesser Weever.
(PI. xlvii., fig. 8; PI. xlviii., fig. 15; PI. xlix., figs. 31, 32; PI. l., figs. 37, 38.)

Ova, which have been identified with this species from Brook's description, §
occurred in considerable abundance in the surface-nets in Blacksod Bay on the
15th June and 11th July; in Inver Bay on the 25th, 28th, and 29th June; in
Clew Bay on the 30th June ; and on several other occasions in these bays.

The diameter is 1 "25-1 '37 mm. ; the yolk is clear, colourless, and homogeneous,
and there are (fig. 31) from eleven to nineteen small pale greenish-yellow oil globules
(the largest "06 mm. in diameter) scattered over the upper hemisphere of the yolk.
Seen by the naked eye, the globules give a dull yellowish colour to the egg, very
similar to that of the common sole's egg. The egg-capsule is thin, but tough and
resistant.

In flattened preparations, under a high power, an optical section shows that
it is divisible into an outer homogeneous layer (fig. 8, v. m.) and an inner layer (st.)
showing four or five stratifications. The two layers are of about equal thick-
ness (fig. 8). Treated with picro-carmine, the outer layer takes only the yellowish
stain, whilst the stratified part is very faintly affected by the carmine. The double
nature of the egg-capsule, in this species, was observed by Brook (op. cit., p. 275),
who considers the outer layer as the vitelline membrane, according to the definition

* British Pishes. Vol. i., p. 89.

f Reproduction and development of Teleostean fishes occurring in the neighbourhood of Plymouth.
Journal of the Marine Biological Association. N.S. No. 1, March, 1889, p. 25.

J Brook. Spawning period of British food-fishes. Report Scot. Pish. Board, 1885.
§ On the development of Trachinus vipera. L. S. Journal Zoology. Vol. xviii. p. 274.

3 Q 2

438

Holt — On the Eggs and Larvce of Teleosteans.

of Balfour. It is doubtful whether it really represents anything more than an
unusually thick lamina of the zona.* The inner layer (st.), in which Brook noticed
no stratifications, is regarded by him as the zona-radiata ; and he remarks that the
two layers are occasionally separated by a space. I noticed an extreme opacity in
the capsule of an apparently healthy egg, which may, perhaps, be accounted for
by such a separation of the layers.

Brook gives from twenty to thirty as the number of the oil globules, whereas,
I found only from eleven to nineteen in a considerable number which I counted,
whilst Raffaelef found only from four to ten in ova of T166 mm. which he
refers to this species, remarking that the slight discrepancy is probably due to
local variation. Brook makes no mention of any colouration of the globules, which
are distinctly yellowish (as in Raffaele's) or yellowish-green (fig. 31) in my
specimens, both early and advanced. I noticed one exception in which, at a very
early stage, the globules were colourless, but acquired an unusually pale yellowish
tint as development proceeded. As regards development, I have little to add to
Brook's excellent account.

Pigment of a pale yellow colour (black by transmitted light) appears in minute
round chromatophores in the embryo before the outgrowth of a free caudal region,
and spreads outwards from the sides over the yolk sac, the whole of which is
eventually studded with it (as in fig. 32). When the embryo possesses a free
caudal region equal to the rest of its length, the yellow chromatophores have
become larger and stellate, with a brilliant orange hue (brown by transmitted light);
they extend dorsally and ventrally along the free caudal region almost to its posterior
extremity, and along the gut on either side. Small black chromatophores (fig. 32)
have also appeared, following the course of the yellow pigment in the postanal
region, and distributed sparingly and somewhat irregularly over the anterior part
of the body. Stellate black chromatophores, much less abundant than the yellow,
occur on the yolk sac. Thus, at a comparatively late stage of development in ovo,
the yellow pigment is altogether in excess of the black, a condition which is
reversed in the older stages. The black chromatophores of the trunk become
stellate and increase greatly in size ; they appear on the brain, about the eye and
the large otocysts, on the base of the pectorals, and on the pelvic fins, whilst the
yellow pigmentation of the trunk appears to diminish.

In the recently extruded larva (fig. 37), still mouthless and with comparatively
large yolk (g), the black pigment of the trunk forms a conspicuous line, dorsally
and ventrally, from the pelvic fins to the commencement of the posterior fourth of

* Cf. H'Tntosh and Prince, " On the Development and Life-Histories of the Teleostean Food and other
Fishes," Trans. R. S. E., vol. xxxv., pt. iii. (No. 19), p. 671.

f " Le nova gallegianti e le larve dei Teleostei nel golfo di Napoli.," Mittheil. a. d. Zool. Stat, zu
Neapel., Bd. viii. 1, p. 30.

Holt — On the Eggs and Larvae of Teleosteans.

439

the notochordal region, thus differing from the condition shown in Brook's newly-
hatched larva {op cit., pi. 6, fig. 27). Thereafter the black pigment of this region
tends to become concentrated into two bars — one midway along the post-anal
region, and the other above the anus, sending dendritic lines on to the dorsal fin,
which apparently mark the site of the future first permanent dorsal fin (fig. 38, d. I.).
This is the condition when the postlarval condition is reached (fig. 38) when all
yellow pigment has disappeared, except three patches along the margin of the
embryonic-dorsal fin. The eyes are black, and the roof of the abdomen and the
rectum are profusely pigmented. There is, thus, at this stage, no practical
difference from the condition shown in Brook's figure of an embryo of three days
{op. cit., pi. 6, fig. 29).

The most interesting condition in this form is the development of the paired
fins. At a comparatively early stage (fig. 15) what appears to be a fold of epiblast
is pushed out from the lateral region of the embryo, occupying about the middle-
third of the pre-anal length, and never, as far as can be seen, extending back to
the region of the embryonic-ventral fin. The anterior and posterior portions of
this fold develop rapidly, forming a couple of slight prominences connected by a
narrow ridge {c. r.). The prominences represent the pectoral (p.f.) and pelvic {pl.f.)
fins, which thus, at their earliest stage, are connected by a continuous epiblastic
ridge, which may even be regarded, as Balfour suggests in Elasmobranchs,* as a
continuous lateral fin.

Though at first equal, f the pectoral soon outstrips the pelvic fin in develop-
ment, and the connecting ridge disappears or becomes very inconspicuous. At
hatching (fig. 37) the pelvic {pl.f.) still retains its original position behind the
pectoral {p.f.), the bases of the two being in the same straight line. As the yolk
is absorbed, the pectoral undergoes the usual rotation, and is carried downwards
and forwards to the clavicular region (fig. 38, p.f.), whilst the pelvic {pl.f), now
growing more rapidly, is similarly rotated, and travels downwards and forwards
to a ventral position a little behind the pectoral ; the assumption of the jugular
position is a feature of later development.

From Brook's account (" L. S. Journal," vol. xviii., p. 298) it appears that the
pelvic fins appear very early in Motella mustela, though this was not noticed by
M'Intosh and Prince {op. cit.) in the same species, nor by Raffaele {op. cit.) in
Motella tricirrata.

Pelvic fins do not appear till much later in all other Teleosteans with pelagic
ova, of which the development has been studied.

* " Comparative Embryology," vol. ii., p. 611.

t Brook speaks of the pelvic fins as appearing later than the pectoral, but both fins seemed to me to be
developed at the same time.

440

Holt — On the Eggs and Larvae of Teleosteans.

The newly-hatched larva (fig. 37) measures 3-27 mm. in total length, the pre-
anal length being 1*49 mm. The marginal fins are of moderate size; the dorsal
commences on the mid-brain ; the caudal is spatulate, with embryonic fin rays,
and there is a very minute pre-anal fin (pa./.). The notochord is multicolumnar.
The oil-globules (o. g.) lie principally along the ventral surface of the yolk.
There is no mouth, and the anus (a.) is imperforate. A small urocyst (w.) is
present.

When the postlarval stage is reached (fig. 38) (about three days after
hatching) the total length is 3*51 mm., the increase being in the post-anal
region. The marginal fins are broader; the dorsal extends to the snout. The
mouth is open, with well-developed jaw and branchial apparatus, and the anus is
perforate.

Raffaele notes that the ova of this species are shed in spring, and take about
eight days to hatch, the last three or four days being spent at the bottom. Brook
(" Spawning Period of British Food Fishes," he. cit.) gives April, May, and early
June as the spawning period on the Yorkshire coast, and June and July in his
Aquarium. Day gives spring. A single egg has been obtained this year at St.
Andrew's in the latter part of July.

Cottimb.
Trigla gurnardus. Grey Gurnard.

The well-known ova of this species *• occurred frequently in the tow-nets, and
many ripe as well as spent females occurred in the trawl. Possibly some of the ova
attributed to T. gurnardus may have belonged to T. cuculus, as Cunningham (op. cit.)
has shown that the ova of these two species are identical in dimensions, whilst his
descriptions of the later development of the latter species afford no distinctive
character. The length of the larva is the same in both, and the great size of the
rudiment of the pectoral fin, which he describes as the most peculiar feature of the
larva, is equally well marked in T. gurnardus.

Trigla hirundo, the sapphirine gurnard, is another species which appears to
spawn about June and July, and probably later, as we obtained several males with
enormously developed testes, which gave them the appearance of pregnant females.
No females were obtained. Couch gives from January to June as the spawning
period of this species.

* Cf. Cunningham, op. cit., p. 11 ; and M'Intosh and Prince, op. cit., p. 806.

Holt — On the Eggs and Larvee of Teleosteans.

441

GoBIID^E.

Gobius nig-er (Linn.)(?) The Black Goby.
(PI. XLvn., fig. 12.)

A post-larval goby, 11 mm. long, occurred in the bottom net in Blacksod Bay
on the 14th June.

From the nature of the pigment, I am inclined to refer it to this species. The
young of G. minntus and G. ruthensparri have been long known at St. Andrews,
though they cannot as yet be with certainty distinguished in their earlier stages.
Their pigmentation is, however, uniformly pale, differing markedly from what is
seen in this specimen. The jaw apparatus is fully developed, but no teeth are
visible. The head is large, with slightly upturned snout ; the lower projects
beyond the upper jaw. A large translucent opercular flap {op.) is present; the
gill arches are serrated. The large otocyst has a dorsal prominence, and shows
considerable resemblance to that of the larval Gobius, figured by me in Ann. and
Mag. Nat. Hist.f The clavicle {cl.) is conspicuous : its inferior half is forwardly
directed, and is overlapped by the opercular flap {op.). The pectorals are very
large and fan-shaped, and the fin-rays are conspicuous, as in the early larva.

The abdomen is contracted, and tapers off from the middle of its length to the
anus {a.), which is somewhat posterior to median. The air-bladder {a. b.) is very
conspicuous as a large ovoidal sac, lying in the sub-notochordal region at the top
of the abdomen. The marginal fins still persist, but the fin-rays of the permanent
second dorsal {d. I.) and ventral {p. v. f.) fins are seen. There is no sign as yet of
the first dorsal ; but this fin, judging from the young of other species, is very late
in making its appearance in fishes of this genus. The notochord is still visible,
but the abundance of pigment renders its structure obscure. The extreme pos-
terior end of the caudal region is slightly turned up, and there is a deeply
pigmented pyriform hypural lobe {hp.) from which, as from the upturned noto-
chordal region, embryonic fin-rays extend into the spatulate caudal fin. There
is a considerable pre-anal fin {p. a. /.). The eyes are black, with dark-greenish
lights. The surface of the head and body is covered with a dull olive-green
pigmentation, which is only absent from the pectoral and marginal fins, opercular
flap, and the tips of the jaws. This green colour is somewhat darker on the top
of the head and abdomen than elsewhere, and small black chromatophores are
distributed pretty thickly over it, except in the upturned caudal region. In
addition to this, four bands of reddish-brown stellate chromatophores cross the
body at various points. The first descends obliquely from the dorsum, passing
just behind the air-bladder to the ventral edge. The second crosses vertically at

* " On the Ova of Gobius," s. 6, vol. vi., July, 1890, pi. vi., p. 39.

442

Holt — On the Eggs and Larvce of Teleosteans.

the level of the anus, and is widest dorsally and ventrally. The third band is not
very conspicuous ; it lies at the commencement of the 2nd third of the post-anal
region of the trunk.

The fourth and last band is the most conspicuous and broadest, embracing the
hypural thickening, and the trunk for some distance in front of this.

From the abundance of the pigment, the body has little translucence. The
reddish-brown, conspicuous by transmitted light, is not distinguishable by reflected
light from the surrounding black pigment.

The general effect to the naked eye is a dark olive-green, crossed by black
bands at the regions described.

Compared with the figure of the larval goby, the anus in this specimen is seen
to be much further back, occupying indeed a position posterior to that seen in the
adult. Such a condition occurs also in late post-larval and young specimens of
Gobius ruthensparri and G. minutus.

The ova of Gobius niger are figured in the note previously referred to.*

Callionymus lyra (Linn. ). The Dragonet, &c.

(PI. li., figs. 40-42.)

A few ova of this species were taken in the surface net off Cleggan Head on
the 12th June, in Inver Bay on the 20th June, and in Blacksod Bay on the 10th
July.

The eggs are well known, but the larva has hitherto escaped attention. I was
successful in hatching two eggs on this occasion.

The newly-hatched larva (figs. 40 and 41) has a total length of 2*08 mm., of
which the head and yolk (y.) occupy *895 mm. The snout is as yet blunt, and the
head has the rounded contour usual in early larvae from pelagic ova. The eyes
are comparatively large at this stage, with a conspicuous choroidal fissure. The
otocysts (ot.) are small and oval, and as yet remote from the eyes. The cerebellar
fold is rather large, but the pineal sac is not as yet visible. The heart (h.) is
lodged in a depression of the yolk (g.), which is still very large, '835 mm. by
•595 mm. The yolk sac (g. s.) is rather thick, and exhibits certain irregular nodo-
sities in optical section [of. fig. 40). Faint striae are visible on the surface of the
yolk, which has a slight median lateral constriction. The body has somewhat of
an S flexure (fig. 41), being incurved over the yolk, and upturned midway between
the latter and the posterior extremity. The gut is small, but is tubular for part of

* In this note, while referring to Hoffmann's work on the subject, I overlooked a figure (Taf. nr., fig. 9)
described as the egg of G. minutus. I cannot regard Hoffmann's identification as correct, since he shows
the attachment process as a ring of simple filaments, very different from the reticulate condition of that
structure which I have observed in the ovarian eggs of G. minutus.

Holt — On the Eggs and Larvce of Teleosieans.

443

its length. Its thickened region fails to reach the hinder end of the yolk, and
terminates in a conical process, from which the narrow cord-like rectum (r.~) passes
down along the posterior of the yolk sac to the marginal imperforate anus (a.).

The marginal fins (fig. 41) are of moderate size, and about equal in height with
the free caudal region of the trunk. The dorsal commences behind the otocysts (ot.),
the caudal is short and rounded, and the ventral sends forward a narrow strip
along the postero-ventral border of the yolk sac (y. s.).

The notochord (no. ) is unicolumnar throughout ; the cells do not show the same
ampullation as in the herring, &c. The pectorals have not appeared. The pig-
ment is a bright orange, dark by transmitted light. It occurs in a conspicuous
patch on the snout. There is a well-marked bar (p. h.) extending into the dorsal
fin, across the middle of the free caudal region of the trunk, an arrangement
common to many larval fishes. In front of this, two lines of round chromatophores,
dorsal and ventral, run forward along the sides to the cephalic region, the dorsal
line extending on the top of the midbrain. Similar chromatophores are scattered
over the posterior moiety of the yolk sac, and a few occur on the edge of the
ventral fin near its commencement.

Two large pigment patches occur on the edge of the anterior half of the dorsal
fin, and there are a number of small chromatophores along the bases of the dorsal
and ventral fins about the posterior extremity of the body.*

The newly-hatched larva, whilst presenting resemblances to that of C. festivus
(see Raffaele, op. cit., p. 33) in the character of the pigment and the large size of
the yolk, differs from that form in the possession of a well-developed heart at the
time of extrusion.

Raffaele says nothing definite as to the dimensions of the larva (" piccola "),
nor does he allude to the structure of the notochord in the Mediterranean species.
From his figure of the newly-hatched larva, it is evident that the rectum is even
at that stage separated from the yolk.

I cannot say anything as to the time the egg of C. lyra takes to develop.
In the specimens described above the embr} o was considerably advanced when
taken on the evening of the 20th June, and hatched on the following day. The
faint strise noticed on the yolk surface in the larva may have some relationship to
the vesicular layer of the yolk of C. festivus, though it is remarkable that, if any
trace of such a structure exists in C. lyra, neither M'lntoshf and Prince or
Cunningham should have detected it in the ova. I certainly saw nothing of the
sort in any of the ova that came under my notice.

* Whilst under observation minute tubercles made their appearance all over the integument of this
specimen (as shown in figure 41). Death ensued shortly afterwards.

| The ovum of this species was first described by Professor M'Intosh in the Ann. and Mag. Nat. Hist.
Dec. 1885.

TRANS. ROT. DUB. SOC., N.S. VOL. IV., PART. VII. 3 R

444

Holt — On the Eggs and Larvce of Tcleosteans.

Another egg of this species, which on the 30th June contained an advanced
and pigmented larva, was found twenty-four hours later to have hatched.
The larva (fig. 42) is probably now at least twelve hours old, and shows a
considerable advance on the newly-hatched condition. The total length is
2*20 mm., having increased by -12mm. The yolk is much reduced, and has now
an elongated ovoidal shape, narrowest in front. The fore brain has undergone a
certain upward rotation and the pineal (pn.) is visible as a distinct prominence in
profile. No mouth is as yet present, but the development of a pre-nasal rostrum has
increased the acuteness of the frontal angle, imparting to the head something of
the shovel-like contour familiar in the adult. The hind brain is shortened,
bringing the otocysts (ot.) nearer to the eye. There is as yet no appearance of
the enormous development of the brain met with in older stages,* and the eye is
still comparatively large. The pectorals (p ./.) have appeared as small semicircular
flaps in rear of the otocysts. Beneath them the gut shows a dilatation. The pos-
terior region of the gut now extends some way behind the yolk under the noto-
chord, the cord-like rectum (r.) descending to the marginal imperforate anus (a.)
at a short distance behind the yolk (y.), a condition due to the shortening up, by
absorption, of the latter. The post-anal region measures 1-18 mm., the anus being
slightly anterior to median.

The marginal fins have undergone considerable expansion, especially the dorsal,
which now commences at the snout, passing up over the fore- and mid-brain as a
narrow fold, and thence increasing till it reaches its greatest height above the
posterior extremity of the yolk. The embryonic caudal fin is not affected by this
expansion, but embryonic fin rays have appeared in it (fig. 42).

The arrangement of the pigment has undergone certain changes. The chro-
matophores over the posterior two-thirds of the yolk sac have become stellate.
Pigment has appeared round the inner edge of the iris. The body pigment is
now restricted to the neighbourhood of the otocysts, the post-anal band (p.b.),
which is more conspicuous, and the caudal extremity, where the chromatophores
are now aggregated into a dorsal and ventral patch. The two lateral lines of
chromatophores in the anterior region have disappeared, or have in part migrated
to the posterior extremity of the tubular part of the gut, and the narrow rectal
region. One chromatophore occurs on the pectoral fin.

The two marginal patches of the dorsal fin have increased in size, but have
migrated backwards, and now occupy the extremities of the central third of the
expanded portion of the fin (i. e. the part between the mid-brain and caudal fin).
A large marginal patch has appeared on the ventral fin below the post-anal bar, and
small chromatophores occur along the edge of the fin from this point to the

* Cf. M'Intosh and Prince, op. cit., p. 864.

Holt — On the Eggs and Larvae of Teleosteans. 445

yolk. None of the darker pigment characteristic of the older forms has as yet
appeared.

No striations of the yolk are visible in this specimen. Compared with Raffaele's
figure of a larval C. festivus on the second day after hatching, it is seen that the
marginal pigment patches of the dorsal and ventral fins are characteristic of both
forms. In the Mediterranean species the development of the brain, and in our
own that of the snout, seems the more precocious, the exaggeration of both
structures being characteristic of the older forms of C. lyra.

It may be permissible here to advert shortly to the question of the affinities of
this form. Kaffaele remarks that in development and early conditions it has
nothing in common with the Gobies, amongst which it is classed. The hexagonal
marking of the zona (vitelline membrane), so conspicuous in C. lyra (but absent in
C. festivus), was found by Raffaele also in the fertilized egg of Uranoscopus scaler,
and in the ovarian egg of Saurus lacerta (op. cit.). Putting aside Saurus, Cunning-
ham {op. cit., p. 37) regards the occurrence of this common feature in Callionymus
and Uranoscopus as suggesting " some interesting possibilities with regard to the
true systematic affinities of these two genera," the latter of which is classed with
the Trachinidse. He alludes to certain peculiarities of adult structure common to
the two forms, and points out that whereas the Trachinidse are mostly laterally
compressed, Uranoscopus is depressed from above downwards, and has the two eyes
directed upwards and placed on the flat upper surface of the head. This, it may
be remarked, is equally true of Gobias minutus.

Cunningham concludes that it is probable that "Callionymus and Uranoscopus
are closely allied, and that either the Callionymina ought to be included among the
Trachinidse instead of among the Gobiidse, or that the Callionymina and Uranoscopina
form a single family distinct both from the Gobies and the Weevers." The fact that
the eggs of the typical gobies are adhesive whilst those of Callionymus are pelagic
appears to me of no great weight, as both pelagic and demersal eggs occur in the
Labridse, and even in the single genus Clupea ; and such goby-eggs as are known to
us, so far from being typical, are as aberrant in their own way as those of Callionymus.
That the presence of oil-globules in the ova of Trachinus and their absence in those
of Uranoscopus can be regarded as seriously lessening the chance of affinity between
these two forms appears improbable, as oil-globules are present or absent in the
ova of different species of the same family, such as the Labridse and Gadidae, and
even in the same genus (e. g. Clupea). The occurrence of the hexagonal marking
in Saurus would seem to indicate that no great importance can be attached to this
structure. Saurus is one of the Scopelidse, a Physostomous family having certainly
no close relationships to either of the other forms.

As to the relationships of Callionymus to the gobies it may be pointed out that
the unicolumnar condition of the notochord, by no means a common feature,

3 K 2

446

Holt — On the Eggs and Larvw of Teleosteans.

occurs in both Gobius and Callionymus, though too much stress should not be laid
on a feature which appears in widely separated groups, and is variable within the
limits of a single genus.*

In Callionymus and Gobius, the notochord cells (vacuoles) are smaller and less
inflated than those of the herring, which Kupffer (Entwickelung des Herings im
Ei. Jahresb. Comm. deutschen Meere. 1874—76: Berlin, 1878) has shown to arise
from more numerous and smaller roundish polygonal cells. Of the origin of those
in the dragonet and goby we have at present no knowledge.

Cepolid^;.

Cepola rubescens (Linn.). The Red Riband Fish.

(PI. xlviii., fig. 22.)

A female of this species, 11^ inches long, occurred in the stomach of a large
grey skate in Inver Bay, on the 25th of June. It was somewhat macerated, and
the ripe ovaries, with other viscera, were exposed. A number of ripe ova were
scattered about in the skate's stomach. The ovum (fig. 22) is translucent, with a
thin minutely-pitted zona. The diameter is '72 mm. The yolk (?/.) is homogeneous,
translucent, and colourless, except at the periphery, which exhibits a brownish
opacity in optical section. It is somewhat collapsed, a condition which, with the
brownish tinge, is doubtless due to the action of the gastric juices. The zona
shows no sign of collapse, and appears perfectly spherical. There is a single large
oil-globule, 1*35 mm. in diameter, with a somewhat smoky margin, like that of
Trigla gurnardus.

From its small size, thinness of zona, and character of yolk, I am inclined to
regard this as a pelagic egg. My specimens were, of course, of no service in
demonstrating the buoyancy (or otherwise) of the living egg.

This species is abundant in the Mediterranean, but the ova, if pelagic, have
escaped Raffaele's attention.

* A unicolumnar notochord occurs in Pleuronectes americanus. See Agassiz and Whitman, " The Pelagic
Stages of Young Fishes " — Memoirs of the Museum of Comparative Zoology, vol. xiv., Wo. 1, pt. i., pi. xvr.,
fig. 5. It is not known to occur elsewhere in the Pleuronectidse. In the genus Clupea it is present in
C. harengus, C. sprattus, and C. pilchardus ; but the notochord of C. sapidissima is multicolumnar. See
Ryder, " The Development of Osseous Fishes " — U. S. Commission of Fish and Fisheries, pt. xiii.,
Report of Commissioner for 1885, p. 523.

Holt — On the Eggs and Larvae of Teleosteans.

447

GOBIESOCID^E.

Lepadogaster bimaculatus (Donov.). The Doubly-spotted Sucker.

(PI. xlvii., figs. 1-7.)

On the 12th June a whelk-shell was obtained in the trawl in Clifden Bay, and
proved to contain a specimen of Lepadogaster bimaculatus. On breaking the mouth
of the shell a number of ova were revealed, attached to the inside of the last
whorl near its commencement.

The shape of the ova (figs. 1-3) is remarkable. They are not globular, as
described by Hyndman,* but ovoidal and abruptly truncated inferiorly (fig. 1),
having something of the shape of an ordinary dishcover. The length is 1*37 mm.,
the breadtli 1*08, and the height '68 mm., but these dimensions, as also the
contour, are subject to slight variations. There is a single, large, colourless
oil-globule (o.g.) of 24 mm. M'lntosh and Prince [op. cit., p. 672) noted that the
zona shows very evident punctures.

The flattened under- surface of the egg (fig. 4) adheres to the shell by means
of a remarkable attachment apparatus. The micropyle is central, and is closed in
the somewhat advanced stages studied. Its site is visible from below as a minute
clear, oval area (mi.), from the edges of which numerous interlacing fibrils radiate
outwards, forming by the cohesion of their distal ends a structure resembling a
shallow circular basket with a thickened rim (r.p.), from which are given off very
numerous fine filaments (fil.) of considerable length. It is evident that these fila-
ments have an adhesive function in the freshly-extended ovum. In favourable
preparations it is seen that this plate-like structure is continuous with the rest of
the zona only in its centre, i. e. around the micropyle (mi.). In addition to this
central apparatus the whole of the flattened surface of the zona is studded by
numerous short, stout, rod-like bodies (rd.), having rounded bases springing from
the zona, whilst their distal extremities, which are directed towards the periphery,
bifurcate, and thereafter taper very rapidly into long and extremely fine adhesive
filaments (fil, fig. 4) similar to those of the central structure. These can be seen,
in an isolated egg viewed from above (fig. 3), projecting as a fringe (fit.) beyond
the edges of the inferior surface. The zona is of moderate thickness, and there
appears to be no layer external to it. Treated with picro-carmine it takes on the
carmine stain faintly, whilst the attachment apparatus is entirely unaffected by it,
with the exception of the thickened rim (fig. 4, r. p.)oi the central structure. This

* This observer gives about -jV inch as the diameter. Day, " British Fishes," vol. i., p. 193.

448

Holt — On the Eggs and Larvae of Tcleosteans.

is somewhat remarkable, as the attachment process in the egg of Gobius* takes the
carmine stain very deeply and readily.

The yolk (y.) is colourless and translucent, and very finely granular. The
oil-globule (o. g.) appears to occupy a variable position, as in some other demersal
ova ; the embryos in different ova at the same time present such differences in
development as to induce the belief that the parent deposits them in batches from
time to time. Judging from Mr. W. Anderson Smith's account (Notes on the
Sucker Fishes, Liparis and Lepadogaster : Proc. Roy. Phys. Soc, Edin., vol. ix.,
1886, pt. i., p. 145) the eggs of L. decandolii are all deposited at the same time, as is
the case with most demersal ova. In some of the ova before us the embryo at the
time of capture had a long, free, caudal growth, others had no free caudal growth,
and only four protovertebrae (fig. 3), whilst intermediate stages occur. In the
least advanced stages a large Kupffer's vesicle (k. v.) was present. The embryo
occupies a horizontal position in the egg, the yolk (y.) being laterally compressed.
Mr. Anderson Smith notices great irregularity in position in the embryo in the
eggs of Lepadogaster, but in my specimens the horizontal position appeared
constant. I did not experience the difficulty met with by that observer in
isolating the ova of this species ; on the contrary these appeared much easier to
isolate than such demersal ova as those of Centronotus, which adhere to each other,
and possess no attachment processes.

The larva, on emerging (figs. 6 and 7), has a total length of 2*97 nrm.,-]* of
which the pre-anal region occupies 2*08 mm. The yolk (y. and fig. 5) is small,
transversely elongated, and somewhat bilobed. Anderson Smith noticed that it is
smaller than in L. decandolii. The head is large, and the parts of the brain are easily
made out, the medulla (m. o.) rising to a conspicuous hump behind the cerebellum.
The eye is large, with a comparatively large pupil. The otocysts are large and
near the eyes. The top of the head and back are very much flattened, a condition
well shown in a dorsal view of the larva (fig. 7). The pectorals {p.f.) are stout
and fan-shaped. The gut, which extends far back, is very large ; the anus (a.) is
perforate. The mouth (m.) is subterminal, and the turning up of the mandibular
symphysis below, and short of, the anterior extremity of the upper jaw imparts a
characteristic appearance to the head. The marginal fins are narrow ; the embry-
onic caudal somewhat lanceolate, and a very narrow pre-anal fin (p. a.f.) extends
from the yolk to the anus. The only pigment I could detect is black, and takes
the form of small round chromatophores. These occur on the lower jaw, along
the ventral region of the yolk sac on the pectoral fin, dorsally and ventrally on
the gut, and in four ill-defined rows along the sides of the body, except at the

* Cf. " On the Ova of Gobius "—Ann. and Mag. Nat. Hist., July, 1890, p. 37.
\ Some as long as 3- 1 5 mm., and advanced in pigmentation.

Holt — On the Eggs and Larvae of Teleosieans.

449

extreme posterior end. Of these four rows the most dorsal marks the boundary of
the flattened dorsal region, and extends forward on to the mid-brain {m. b.);
whilst posteriorly several chromatophores occur between the two rows. Post-
anally the ventral rows unite to form a single line along the ventral edge of this
region.

The pigmentation of the eyes is variable : in some larvse there are only a few
chromatophores on the iris, which is perfectly black in others.

There is considerable resemblance to Mr. Anderson Smith's figure of the larva
of L. decandolii. The gut appears to extend further back in our species. Mr.
Anderson Smith also figures ova of L. decandolii, from which it appears that they
are nearly circular, and contain a single large oil-globule. He mentions that they
have a pinkish tinge, which distinguishes them from those of L. bimaciclatus, but
he gives no dimensions of the eggs or larvse of either species, and does not allude
specially to the shape nor to the method of attachment of the eggs. He points out
that both species spawn in June and July, and that the ova are hatched in twenty-
eight days. Those of L. bimaculatus, according to the same authority, are almost
always arranged in regular layers (a condition which I did not notice in my
specimens), within the empty shells of Pec ten opercularis. Day, on the authority
of Mr. Hyndman, records them from the shells of Venus virginea and Pectunculus
pilosus.

Labrid^e.

Labrus maculatus (BL).* The Ballan Wrasse. The Gunner (Mayo Coast.)

Raffaele [op. cit., p. 35), observes that the ova of Labrus (X. ?nerula, &c), and
Crenilabrus ( C. griseus, C. ?nediterranus, and C. pavo) are demersal, the former being
adherent, and the latter non-adherent.

Day (op. eit.j vol. i., p. 253) gives the breeding season of L. maculatus on the
Galway coast as about June, and quotes Moreau to the effect that this species and
L. mixtus form nests for the reception of their spawn.

Day's observations on the breeding season are to some extent confirmed by our
own experience. We obtained specimens only on one occasion, the 8th July, at
Inishkeagh.

They were all spent, males and females alike; but several of the females
appeared to have spawned recently, judging from the condition of the few ova
which, as usual, were retained in the ovaries. They are spherical, and the
diameter is from 1*01 to 1*07 mm., in some instances reaching 1*13 mm.

In most the egg contents are reduced to an opaque ochreish granular mass,
occupying the centre of the egg, whilst in a few of the larger ones the yolk has a
diameter of 1-01 mm., and is colourless and translucent, except for an irregular

* See note on p. 473.

450

Holt — On the Eggs and Larvce of Teleosteans.

central opacity. In some the yolk fills the entire available space, as in fresh ripe
ova before fertilization. The zona is somewhat thick, and minutely punctured.
No external membrane or attachment process can be made out, and it is to be
supposed that the ova, if adherent, as in the Mediterranean species of this genus,
are so in virtue of a viscous oviducal secretion, as in Cottus, Cyclopterus, &c. The
yolk is extremely resistant in spirit preparations, and appears to possess a thin
outer membrane (periblast), having a dotted surface presumably corresponding to
the punctures of the zona.

Crenilabrus melops (Linn.). The Cork-wing Wrasse, &c.

On the 12th June I obtained some apparently ripe ova from females of this
species in Clifden Bay. They were colourless and translucent, and the yolk
appeared perfectly clear. No oil-globule was present. Unfortunately my
measurements of these ova have been mislaid.

On the 7th July I again obtained some females in Blacksod Bay. In one of
them the ova appeared about three-quarters ripe ; they were opaque and ochreish
yellow, ovoidal in shape, having a long and short diameter of "60 mm. and *48 mm.
respectively. The other females were either spent or immature.

It is noticeable that this species comes to maturity at a very small size. Of a
number that I examined, both male and female, every specimen exceeding 4 inches
in size had well-developed reproductive organs, either approaching maturity or
recently spent. A male of 10 inches, the largest obtained, had partly spent
testes.

From the spent females I obtained a few eggs that had been retained in the
ovaries, as happens frequently in Teleosteans.

They are spherical, with a diameter of *78 mm. The yolk is colourless, but
has a milky- white opacity, probably due to incipient decomposition.

The zona is, as usual, covered with minute punctures. There is no attachment
process, and optical sections do not show the division of the egg-capsule into two
layers, such as Hoffmann (Zur Ontogenie der Knockenfische, p. 18, Verhand.
Konink. Akad. v. Wetenschappen, 1881) found in C. pavo. According to this
observer, the egg of the latter has a diameter of '75—78 mm., while the newly-
hatched larva is 3*6 mm. long. List (Zur Entwickelungsgeschichte der Knocken-
fische, I. Labriden; Zeit. f. wiss. Zool., vol. xlv., 1887, pp. 595— 645) examined
the ova of five species of this genus from the Adriatic, and gives an excellent
account, with figures, of the development in ovo of C. tinea and C. pavo. He gives
•9 mm. as the diameter of the egg of the former, remarking that that of the latter
is somewhat larger, thus disagreeing with Hoffmann's measurements. The yolk
appears to be yellowish in both species. At hatching the larva of C. tinea is

Hol x — On the Eggs and Larvae of Teleosteans.

451

2*5 mm. long, that of C. pavo being longer and more advanced. In both the
mouth is unformed, the notochord is multicolumnar, and the anus posterior to
median, with a considerable embryonic pre-anal fin. In addition to yellow pig-
ment, there are very large stellate chromatophores of bright blue, a colour not
usually met with in body pigment of teleostean larvse. There is no pigment on
the marginal fins.

List further observes that the zona is divisible into two layers — the outer
consisting of regular hexagonal prisms, whilst the inner is faintly stratified.
M'lntosh and Prince [op. cit., p. 673) show that the zona of Liparis montagui
exhibits similar hexagonal markings, but do not record an inner layer. The
condition recalls that of Callionymus and other forms.

Gadid^e.

Merluccius vulgaris (Cuv.). The Hake.

A female with nearly ripe ovaries occurred in the trawl in Inver Bay, on the
25th June.

A few translucent and apparently ripe ova were obtained ; they were not quite
spherical, having a long diameter of 1*35 mm. and a short diameter of 1*08 mm.,
with a single large oil-globule of '30 mm.

Raffaele [op. cit., p. 37) gives 0*94— 1-03 mm. with oil-globule •27 mm. as the
dimensions of the ova of this species, which he describes as spherical.

The spheroidal condition of my ova was perhaps abnormal, as they were not
perfectly fresh when measured, but they were certainly larger than in the Medi-
terranean form.

According to Raffaele this species spawns at the end of January in the Medi-
terranean. Brook gives March to May, and June to September as the spawning
period on the west and east coasts of Scotland, respectively, quoting Couch to the
effect that the period on the Cornish coast is August.

The large size of the oil-globule renders this a very conspicuous egg, which
should be easily recognized if obtained in the tow-nets.

Mackurid^.

Macrurus, species ?

Amongst the contents of the trawl from 450 fathoms off Achill Island, on the
10th July, were two large females, of a species not yet identified,* with enlarged
ovaries.

* Since identified as M. rupestris.

1B.AXS. EOT. DUB. SOC, U.S. VOL. IV., PART VII. 3 S

452

Holt — On the Eggs and Larvae of Teleosteans.

The eggs, which appear about three-quarters ripe, or less, are spherical, opaque,
and whitish. The diameter in the largest is from 1*25—1*31 mm. There is as
yet no appearance of a single oil-globule, though oleaginous matter is, as usual,
abundant in the egg contents. The zona, surrounded by the granulosa, is thick
and multi-laminate, with very conspicuous radial pores, terminating in minute
surface punctures. There is no trace of the mosaic of concave hexagonal facets
described and figured by RafTaele (op. cit, p. 65) in his species No. 4, attributed
to this family, nor does an optical section show the tubercles found by Costa on
the ovarian egg of M. coelorhynchiis. My specimens, however, had still a consider-
able period of intra- ovarian life before them.

Pleuronectid^;.

Rhombus lsevis (Rondel). The Brill or Britt.

(PI. xlviil, figs. 13 and 14.)

A female was obtained in Blacksod Bay on the 16th June, and proved to
contain ripe ova : I could not fertilize them, as no ripe male occurred on the same
occasion.

The ripe unfertilized egg (fig. 13) floats buoyantly, and has a diameter varying
from 1*25 mm. to 1*37 mm., with a single pale oil-globule {o.g.) of *21 mm., which
in some cases shows a faint, dull-yellowish colouration round the edge. The yolk
is colourless, clear, and homogeneous. The punctures of the zona are very evident,
and the radial pores are very conspicuous in optical section ; the zona has the
appearance of being very much wrinkled, as is the case in some ova before fertili-
zation. Examination of flattened ova under a high power shows that whilst the
external surface is smooth, the zona is not of uniform thickness throughout, the
internal surface being raised into ridges, similar to, but more jDronounced and numer-
ous than, those in the unfertilized ova of Pleuronectes cynoglossus. This may be due to
artificial causes. This observation may, I think, be taken as confirming Raffaele's
surmise {op. ctt., p. 48) that certain pelagic ova (having a diameter of 1*32 mm.,
with an oil-globule of *21 mm.), taken by him at Naples in the summer, belonged
to this species. The differences of measurement are insignificant. MTntosh and
Prince (op. cit, p. 847) obtained similar ova at St. Andrews in February and
March, so that the spawning season of this form appears to extend over a consider-
able period in the British Isles.*

* Dr. T. Weinyss Fulton records a ripe female in May, from the mouth of the Forth — (" Spawning and
Spawnmg-places of Marine Food-fishes," Eighth Annual Report of the Fishery Board for Scotland, 1880,
pt. iii.).

Holt — On the Eggs and Larvce of Teleosteans.

153

A single egg (fig. 14) apparently belonging to this species, with diameter 1-31,
and oil-globule *21 mm., occurred in the surface-net in Clew Bay on the 2nd
July.

The zona in this specimen exhibits nothing of special interest ; the perivitelline
space is small ; the embryo is little advanced, with about four protovertebrse : no
pigment is present; the oil-globule has migrated a short distance towards the
posterior region.

Pleuronectes microcephalus (Donov.). The Lemon Dab, or Lemon Sole.
PI. xlviil, figs. 19-21 ; PI. l., fig. 39.

Pipe females were obtained frequently, yielding an abundance of mature ova.
Some which I measured on the 25th June had a diameter of 1*25 mm.,* being thus
smaller than those measured by Mr. Cunningham, at Plymouth^ (pp. cit., p. 15).
I endeavoured to fertilize these, but without success. Four hours later they were
still translucent and floated buoyantly, whilst in a few a small perivitelline space
had appeared, as after fertilization.

Cunningham (ibid.) points out that " the external surface of the vitelline mem-
brane shows a number of fine raised ridges forming two systems of parallel lines
which cross one another diagonally." M'Intosh and Prince give a figure (op. cit.,
PI. i., fig. 18) of part of the zona under a high power, showing a somewhat
irregular reticulation of lines, seen as white spaces on the closely dotted surface.
The latter condition is more in accordance with my own observations. Examina-
tion of the zona in the living egg (fig. 21) certainly gives the impression described
by Cunningham, but if it is ruptured and flattened out, it is seen (fig. 20) that the
markings are extremely irregular. There are certainly two general systems of
parallel lines, but these lines are by no means continuous, frequently ending
blindly, converging and diverging, or bending abruptly to continue their course
at a different level. Seen from above the markings appear as a line on to which
the thickly-set punctures of the rest of the zona do not extend. By tracing the
lines to a point where the zona is doubled over so as to present an optical section,
it is clearly seen that they are not ridges at all, but sharp grooves indenting the
surface of the zona from about a quarter to a half of its thickness, according to
the size of the lines, which are of varying widths. In some instances the sides of
the grooves are very slightly raised above the general surface level.

By the kindness of Professor M'Intosh I have been enabled to add to my

* Some dead fertilized ova of this species in the tanks here measured from 1*2 to 1*31 mm.
f Mr. Cunningham gives 1'36 to 1-44 mm., "though individual ova may be a little smaller or a little
larger." In an earlier paper he gives 1*1 mm. as the diameter of the mature (unfertilized) ovum.

3 S 2

454

Holt — On the Eggs and Larva? of Teleosteans.

observations from some ova of this species which he is at present developing. I
cannot find these markings in ruptured zonae, from which the larva has escaped,
and they are very faint in dead and decomposing ova.

Only a single egg (fig. 19) of this species, with a diameter of 1*25 mm., and
showing the peculiar marking of the zona, occurred in the tow-nets, viz. in the
surface-net, in Inver Bay, on June 25th.

It is at a stage somewhat in advance of that shown by Cunningham in his
figure 7 {op. cit.), having a free caudal region about equal to the rest of the body,
and a broad marginal fin. Pigment is altogether absent, though black chromato-
phores are shown by Cunningham in the figure alluded to, having first appeared
on the previous day.

Professor M'Intosh pointed out to me long ago that a temperature slightly
higher than normal frequently brings about a precocity of pigment, a phenomenon
very noticeable in the development of the sprat. This probably accounts for the
difference in the condition of pigmentation in Cunningham's ova and my own,
though the latter, a single specimen, may perhaps be abnormal. Three days later
I found that the larva had escaped, and was darting actively about the vessel,
occasionally resting for a time at the surface.

It is now (fig. 39) apparently at a stage between those shown by Mr. Cunning-
ham in figures 8 and 9, and does not altogether agree with his descriptions. The
length is 3*98 mm., a little longer than Mr. Cunningham's newly escaped larva.
The snout projects boldly, but the mouth is as yet unformed, though/the branchial
bars are visible. The mid-brain (m. b.) is rather prominent dorsally, its greatest
height being behind, instead of in front of, the middle of the eye, as in Cun-
ningham's figure 9. The nasal sacs {ol.) are apparent just in front of the eyes,
which to some extent overlap them. The otocysts, which are omitted in
Cunningham's figure 8, are large, of the usual shape, but somewhat upwardly
rotated on the hinder ends, and lie a little distance behind the eye. The pectorals
(p.f.) are considerably developed, they have undergone a partial rotation, and are
somewhat in advance of the position at which these organs usually make their first
appearance.

The gut is large and tubular. It displays two dilatations close behind the
pectoral fins, representing the liver and stomach. The intestinal region of the gut
is very ample, and there is a sharp constriction immediately in front of the rectal
region (r.), which ends blindly short of the margin of the ventral fin, appearing in
this respect to be somewhat abnormal. The anus is as yet imperforate, and there
is no appearance of an urocyst. The yolk (y.) is narrow and elongated, and the
space in front of it, spoken of by Cunningham as the venous sinus, is much smaller
than in either of his figures. The posterior end of the heart (h.) is against the
front wall of the yolk. The marginal fins are rather narrow, the dorsal com-

Holt — On the Eggs and Larvae of Teleosteans.

455

mences just behind the level of the otocyst; the caudal is short and narrow, and
almost lanceolate. Pigment is of two kinds, black and grass-green (chrome-
yellow by transmitted light). The yellow is generally distributed over the head
and the anterior and postero-ventral parts of the yolk-sac. From the otocystic
region, dorsal, renal, and ventral-intestinal lines of chromatophores run back
to the anal region. The post-anal region is crossed by three pigment bands
[p. b.), the most anterior of which is rather feebly marked. A few large chroma-
tophores occur on the anterior part of the dorsal fin. Black pigment is found in
stellate chromatophores on the top of the head and about the otocyst ; antero-
ventrally on the yolk-sac, and along the ventral edge of the gut. There are dorsal
and post-anal ventral rows of black as far back as the end of the second pigment
band, the former reappearing above the third and last band.

Pleuronectes cynoglossus (Linn.). The Pole Dab, or White Sole.

The ova of this species were first obtained by Mr. J. T. Cunningham in the
Clyde, and are described by him in a Paper " On the Eggs and Larvae of Teleos-
teans" (Trans. R. S. E., pt. i., vol. xxxiii., p. 101). He gives 1*155 mm. as the
diameter after the formation of the perivitelline space.

The trawl brought up some ripe females in Donegal Bay on the 26th June. I
found that the diameter in the ripe unfertilized egg varied from L07 to 1*13 mm.
The yolk is clear and homogeneous, and the zona has an appearance of close
longitudinal striation. In stained spirit preparations under a high power the
striation can be reduced to numerous short line-like markings, lying close side
by side, with overlapping ends. They appear to be due to the fact, shown in
optical section, that the internal surface of the zona is raised up into numerous
minute ridges. This condition, which is met with also in the unfertilized egg of
the brill, may perhaps disappear with the formation of the perivitelline space, or
may be due to the action of reagents ; the striation, however, is as well marked in
fresh as in preserved specimens.

Clupeid^:.
Clupea sprattus (Linn.). The Sprat.

The ova of this species occurred in the surface net in Inver Bay on June 25th,
and in Clew Bay on the 30th June.

Numbers of young sprats between 2 and 3 inches long occurred in the stomach
of Acanthias on the latter occasion.

456

Holt — On the Eggs and Larvce of Teleosteans.

Olupea harengus (Linn.)- The Herring.

A post-larval herring, 1^- inches in length, occurred in the trawl in Birturbuy
Bay in the early part of June.

Syngnathid.e.

Siphonostoma typhle (Linn.). The Broad-nosed Pipe-fish.

This species was found to be very common amongst the Zostera beds in Clew
and Blacksod Bays on the 2nd and 6th July. A single specimen was taken in the
shrimp trawl in Killybegs Bay on the 23rd June. Many of those taken in the
Zostera beds presented an exact imitation of the colour of the Zostera. All the
males observed carried either well- advanced ova or young. The latter were of
different sizes in different parents, some being so far advanced that they readily
quitted the parent in the bucket in which they were placed on capture. Ryder
has described the development of an American species (S. fuscum) [op. cit., p. 508).

Syngnathus aeus (Linn.). The Great Pipe-fish.

Abundant in the same locality as Siphonostoma tgphle, and agreeing with it in the
condition of the eggs and young. This species occurred also at Inishboffin and
other places, and was obtained whenever the shrimp trawl was worked on weedy
ground. Young specimens were occasionally obtained in the surface-net, amongst
floating weeds, in Blacksod Bay.

Nerophis eequoreus (Linn.). Snake Pipe-fish.

Abundant in the Zostera beds, on the same dates as the Siphonostoma. Many
of the males carried ova more or less advanced. As in Siphonostoma, the coloura-
tion, save for the transverse bars, presents an exact mimicry of the surrounding
Zostera. The same condition was noticeable in specimens of Hippolyte varians.

Nerophis lumbriciformis (Willugh). Worm Pipe-fish.

Specimens of this species occurred frequently. A few males, taken amongst
the rocks in Killeany Bay, Aran Islands, carried advanced ova (3rd June).

Holt — On the Eggs and Larvce of Teleosteans.

457

Unidentified Pelagic Ova.
Species I. — Solea(?)
(PL xlix., fig. 26 ; PI. l., figs. 34 and 35.)

A single egg (fig. 26) occurred in the surface-net, in Clew Bay, on the 1st
July, 1890. The diameter is 1*38 mm. The embryo is somewhat advanced, but
has only a short free caudal growth. The zona presents no characters of special
interest, and the perivitelline space {p. s.) is small. The yolk (y.) has a peripheral
layer of clear segments or vesicles (c. v.), which appear somewhat smaller and
more numerous than those of Solea vulgaris. A number of oil-globules are present
about the periphery of the yolk mass. They are divisible into two sorts : —
(1) Very minute globules {o.g. 1), arranged in little groups in the immediate
vicinity of the embryo, viz. beneath the head and close to the sides of the anterior
third of the body, with the exception of one very small group near the posterior
extremity. (2) Larger globules of varying sizes (o. g. 2) scattered irregularly over
the general yolk surface. The lens is fully formed, but the otocysts are as yet not
visible. A few small black chromatophores occur on the head ; and bright-yellow
chromatophores are profusely scattered all over the embryo, and on the parts of the
yolk-sac immediately adjacent to the head and trunk. There is no pigment on
the rest of the yolk-sac.

Four days later, on the morning of July 5th, the larva was observed to have
emerged. On the afternoon of the same day it presented the following appearance
(fig. 34). Total length 4*10 mm., of which '30 mm, is occupied by a precephalic
expansion (/.) of the marginal fin, to be hereafter described. The post-anal length
is 2*10 mm., the anus («.) being thus slightly anterior to median.

The cephalic contour is remarkable. The mid-brain (m. b.) is relatively
enormous, and projects forward in a blunt point, overhanging the downwardly
directed fore-brain (/. b.) ; the cerebral lobes are large and rounded; the pineal
sac is scarcely visible, being masked by other structures. The eye is large, and is
antero-ventrally directed : its posterior moiety lies behind the hinder end of the
optic lobes {m. b.), — a ver}' unusual relationship. The cerebellar fold cannot be
distinguished, but the hind-brain (m. o.) is very large and prominent. The elon-
gated inferiorly concave otocyst (ot.) lies close behind the eye. No mouth is
visible, but the branchial bars (b. b.) and slits can be distinguished. With the
protrusion of the brain, the anterior end of the notochord is carried forward. A
large vesicular expansion (/.) of the marginal fin extends forwards over the head,
in front of which it projects like a large bladder. By the aid of dorsal (fig. 35)
and profile (fig. 34) views its relationships can be pretty well made out. The

458

Holt — On the Eggs and Larvce of Teleosteans.

greatest width is in front of the mid-brain ; and the posterior limit is about the
level of the crystalline lens. Ventrally it is dilated below the free part of the
mid-brain, the inferior contour running from a point a little above the cerebral
lobes to the top of the eye. A short median fold is directed downwards in front
of the pineal region. The heart (h.) is large and active. Its hind end rests
against the yolk (?/.), which is reduced and pyriform, anteriorly blunt, and
still exhibits very clearly the ovoidal peripheral segments (c. v.) The smaller
oil-globules have disappeared ; the larger ones are scattered over the general
yolk-surface, principally at the posterior end. A few largish ones at the front of
the yolk very probably represent the coalesced smaller globules.

The pectoral fin (p.f.) is fairly large, but as yet simple; it lies on the dorsal
wall of the abdomen, with obliquely rotated base, a little behind the level of the
front of the yolk mass. The gut is large and perforate except at the anus. It is
bent down in the middle of its length, just in front of which point occurs a large
dextral sac (s.) apparently representing the cardiac dilatation of the stomach. Pos-
teriorly the rectum (r.) descends obliquely towards the edge of the marginal fin,
which the imperforate anus does not quite reach. The long narrow urocyst (u.)
lies against the posterior wall of the rectum. The notochord is multi- columnar
with largish cells, and is rather stout. From the pre-cranial vesicle (/.) the dorsal
marginal fin rises in a gentle ascending curve till it reaches a point a little
behind the pectorals, where its height is '48 mm., the total height of body with
yolk and fin being 1*08 mm. Thence the fin descends gradually to the broad
rounded caudal lobe, in which embryonic fin rays have appeared. The ventral fin
has about the same dimensions as that part of the dorsal which is opposite to it.
Just behind the anus the trunk is about "24, whilst the dorsal and ventral fins are
each about '39 mm. in height. The pre-anal fin, extending nearly half-way along
the yolk, is somewhat broader. The anterior three-quarters of the head and trunk
is covered with profuse dendritic pigment of a bright gamboge-yellow colour ;
there is a very bright patch [p, b.) at the end of this region, from which ramifica-
tions extend on to the dorsal and ventral fins, anastomosing with a large chromato-
phore on each fin. The rest of the trunk is little pigmented. Round yellow
chromatophores are distributed over the general surface of the yolk-sac, dendritic
pigment covers the pre-cranial vesicle and pre-anal fins, and there are six and four
large patches along the margins of the dorsal and ventral fins respectively.

A few small stellate black chromatophores occur on the fore- and mid-brain,
about the commencement of the notochord, over the yolk-sac and along the ventral
edge of the hinder third of the gut. Black pigment also occurs in faint lines
along the sides of the pre-cranial vesicle. No black pigment occurs on the eye.

I cannot say anything definite as to the age of this larva, except that it is more
than six hours old.

Holt — On the Eggs and Larvae of Teleosteans.

459

It is difficult to refer this specimen definitely to any species. The measurements
of the ova of Solea vulgaris given by various authors are somewhat conflicting.
M'Intosh and Prince (op. cit., p. 848) give "045 in. (roughly about l-125mm.).
A number which I pressed from a female and artificially fertilized measured
between 1*31 mm. and l'40mm. ; and others taken in the tow-nets at St. Andrews
in June, 1890, varied between l'25mm. and 1*28 mm. Cunningham's measurements
(Reproduction and Development of Teleostean Fishes, p. 18) are 1*41 to 1"51 mm.*

Thus there seems to be in the single species a very great variation, perhaps to
some extent governed by local conditions, as Cunningham's specimens, from
Plymouth, are much larger than any that have come under oar notice here.

Of Raffaele's soles, the ova of his undetermined species, 1. Solea (?) (op. cit.,
p. 63), approaches ours most closely in dimensions, being 1-4 mm. Solea, sp. A
and B, are respectively 1*06 mm. and 1*23 mm. in diameter (pp. 43—45).

In the character of the vesicular layer of the yolk my egg differs from Solea
vulgaris, as described and figured by M'Intosh and Prince, and as observed by
myself at this place, in that the segments appear to be smaller and more numerous ;
but Cunningham (op. cit.) has shown that in this matter Solea vulgaris is subject to
individual variation. In my form the segments persisted some time after hatching
as conspicuous objects, a condition different to that indicated by M'Intosh and
Prince.

As regards the oil-globules, the presence of groups of minute globules along
the sides of and under the embryo is a marked character of S. vulgaris, and of
Raffaele's sp. A and B, whilst it is wanting in his sp. 1.

The presence of larger globules over the general yolk surface is peculiar, as
though M'Intosh and Prince's figure (op. cit., PI. ir., fig. 11), shows that in
S. vulgaris larger globules are present in the later stages of development (doubtless
by coalescence of smaller), yet in that form they are grouped with the smaller
ones, mostly about the ventral surface of the embryo, a condition which is not
found in our form even after extrusion. The colour and arrangement of the
pigment is very different from that of S. vulgaris.^

The egg of Solea variegata,% described by Cunningham, approaches this form
very closely in dimensions, being only *02 mm. smaller, but differs in the
character of the oil-globules.

* In his " Treatise on the Common Sole," Plymouth, 1890, p. 84, this observer gives the dimensions
as 1*47 to 1"51 mm.

t M'Intosh and Prince (op. cit.) describe and figure the pigment of the larval S. vulgaris as a stone-
grey, a condition in accordance with my own observations. Cunningbam (" Treatise on the Common Sole,"
pi. xn., figs. 3 and 4) figures the pigment as a brilliant orange, and does not allude to the work of previous
observers.

I In his recent work, Cunningbam gives the dimensions of this egg as 1-28 to 1-36 mm., and figures
both eggs and larvae.

TRANS. EOT. DUB. SOC, N.S. VOL. IT., PART VII. 3 T

460

Holt — On the Eggs and Larvce of Teleosteans.

The remarkable forward projection of the mid-brain in the larva seem to
separate it from any other known form.

M'Intosh and Prince {op. cit., p. 851), call attention to a dorsal prominence of
the optic lobes, imparting a hooded aspect to the head of a larval sole four days
old, and Raffaele's figure of the larva of Solea, sp. A, indicates a condition some-
what approaching that in our form. Sp. A also approaches ours in having a " lobo
cefalico rigonfio " of the dorsal marginal fin, and the colour and character of its
pigment appear almost the same. But sp. A not only has a much smaller ovum,
but is much less elongated in its larval stage. M'Intosh and Prince (p. 850)
mention a vesicular process over the brain in one example of S. vulgaris, but regard
it as abnormal.

The spawning period of Raffaele's species A and B extends over autumn,
winter, and spring, and that of his species 1 from June to August.

Cunningham gives March, April, and May as the spawning period of S. vulgaris,
an observation which presumably refers to southern waters. That the period may
be extended on the Scottish coasts is apparent, from the fact that a ripe female
was obtained by Professor M'Intosh on August 1, 1884.

During the six weeks with which this report deals we obtained a considerable
number of soles from time to time, but they were all spent, males and females
alike. A specimen of Solea variegata, obtained early in July, was also spent. Solea
lutea appeared to be ripe during this period, but I have no accurate observations
at present on its ova, as taken from the female, though I am inclined to regard a
much smaller sole-like egg (species II. of this series) as belonging to that form.

The form before us may possibly be a monstrosity of Solea vulgaris, but it is
difficult to regard it in that light, as it differs at once from that species in so many
characters — characters which bring it nearer to the Mediterranean species A.

Solea lascaris, the lemon sole, is regarded by Day as identical with S. impar,
one of the species examined by Raffaele (species A or B ? op. cit, p. 43). The
only other sole recorded from the west coast of Ireland is S. greenii,* a deep-water
form, of which Mr. G. C. Bourne obtained a ripe female in July, 1889.

Species II. — Solea lutea (?) (Risso).
PI. xlvii., figs. 9 and 10. PI. in., figs. 46-52.

These small pelagic ova were obtained abundantly in the surface nets in
Blacksod, Inver, Donegal, and Clew Bays, from the 15th June to the 8th July.

In appearance they exactly resemble Cunningham's figure of the pelagic egg,
which he attributes, doubtless correctly, to Solea variegata [op. cit., PI. ni., fig. 15,
p. 23), but the dimensions are smaller. The diameter is from "775 to "835 mm. (that

* Discovered by Mr. Green in the " Flying Fox " Expedition. 1889.

Holt — On the Eggs and Larvce of Teleosteans.

461

of S. variegata is 1 "36 mm.). The shape is usually spherical, but some are ovoidal,
having a long and short diameter of "835 and *775 mm. respectively. The
numerous small oil-globules (o. g.) are restricted to the vegetative hemisphere,
both in early (fig. 10) and advanced (fig. 9) stages, and are never aggregated at
the sides of the embryo or under it, as in & vulgaris.

The globules are much larger than those in the unfertilized egg of S. vulgaris,
and are quite colourless. There is a cortical layer of yolk segments (c.v.) very con-
spicuous in the early ova,* but becoming less so as development proceeds, though
they are still visible in the early larva (fig. 46).

Raffaele (op. cit., p. 64) describes and figures a pelagic egg, his undetermined
species 2, which presents the closest possible resemblance to this form. Its diame-
ter is '75 mm., thus differing very slightly in size from our form. It occurs at
Naples sparingly in January; I think it more than possible that the two forms
are identical, the resemblances outweighing the slight discrepancy in size.

The period of development in ovo, in the form before us, occupies about five
days. The embryo is at first colourless, but pigment of a faint yellow colour,
black by transmitted light, appears with the first development of the free caudal
region (fig. 9).

It occurs in small rounded chromatophores on the top of the eyes and head, in
a double line along each side of the trunk, and over the general surface of the
yolk-sac. At this stage the otocysts have not appeared, and the lenses are not
invaginated.

As development proceeds the pigment gains in brilliancy, becoming in the
larva a bright-orange, brown by transmitted light.

The larva emerges at an early stage of development (fig. 46). The yolk (y.)
is large and globular, there is no mouth, and the fore-brain is bent down to the
anterior extremity of the yolk-sac. The olfactory apparatus cannot be made out ;
the eyes are of moderate size, and pigmentless, save for a few chromatophores over
the retina. The otocysts (ot.) are small and oval, and remote from the eye. The
contour of the head is rounded, and the medulla rises somewhat above the plane
of the top of the mid-brain. The cerebellum is somewhat large, but the pineal
body is not visible.

The heart (h.) lies immediately behind the eyes, in a depression of the top of
the yolk. It is partially constricted into auricle and ventricle, and is, as usual,
directed to the left.

* These segments appear first at the animal pole, beneath the blastoderm, and extend gradually over
the whole periphery of the yolk. A very early ovum, -which I obtained at St. Andrews on the 30th of
July, showed the oil-globules mostly arranged in a ring at the rim of the vesicular layer, which did not
quite reach the equator. Their subsequent disposition may be in some way due to the extension of the
segments.

3 T 2

462

Holt — On the Eggs and Larvce of Teleosteans.

The gut is somewhat large and tubular, except in the rectal region ; it extends
below the notochord a short way beyond the yolk ; the narrow cord -like rectum (r.)
descends vertically to the marginal imperforate anus (a.), at a short interval from
the hind-wall of the yolk-sac. The oil-globules (o. g.) are, as a rule, restricted to
the posterior region of the yolk, occupying the ventral and ventrolateral surface
of that region, having, as is frequent, undergone a migration backwards from
their original positions.

The marginal fins are somewhat narrow, the dorsal and ventral being about
•12 mm. each, except at the anterior extremity of the ventral, which descends on
to the postero-ventral border of the yolk-sac, becoming thus somewhat deeper.
The dorsal commences at the otocystic region ; the caudal is short and rounded,
with no embryonic rays. The pectoral fins have not appeared. The notochord
is multi-columnar, with small cells.

The pigment, now a bright-orange colour (brown by transmitted light), occurs
in small chromatophores over the head, along the back, and ventral post-anal
region, over the yolk-sac, and on the posterior part of the gut, and at the anus.
It forms a conspicuous bar (p.b.) across the trunk at the commencement of the
posterior third of the total length. Chromatophores occur also on the dorsal, and
sparingly along the edge of the ventral fin.

The total length at this stage is2'02 mm., of which the pre-anal region occupies
•895 mm., the anus (a.) being slightly anterior to median. It is probable that there
is slight variation in the length of the larva on emerging.

A specimen about a day old (fig. 47), has a total length of 2*14 mm., the
increase being entirely in the post-anal region. The yolk is slightly reduced.

At about two days old (fig. 48) the total length is the same as in the last stage.
The yolk is further reduced, and the oil-globules are fewer in number. The snout
is more forwardly directed, and the pineal body is conspicuous. The mid-brain
has gained slightly in dorsal prominence. The otocysts are larger and ventrally
convex. They have undergone a slight upward rotation on their posterior ends,
and, by the shortening up of the hind-brain, are carried nearer to the eye.

The invagination of the stomatodeum has commenced. The pectorals have
appeared as semicircular folds of epiblast (their bases parallel to the notochord),
midway between the snout and the anus. The gut is dilated more conspicuously
in the region of the future stomach (s.), and its thickened tubular character has
extended some way down into the rectum. The chomatophores have now become
stellate, and another pigment bar (p.b.) has appeared across the trunk midway
between the anus and the bar noticed in the newly-hatched larva. The chromato-
phores of the yolk-sac are fewer, but larger than formerly, and those on the edge
of the ventral fin have disappeared. The dorsal fin has extended forward to the
mid-brain, and is much expanded, as are the ventral and short pre-anal fins.

Holt — On the Eggs and Larvae of Teleosteans.

463

Two days later (fig. 49) the yolk is still further reduced, arid very few oil-
globules remain. The total length is now 2-38 mm., the increase being still
confined to the post-anal region. The mid-brain (m. b.)is more prominent dorsally,
and the mouth (in.) forms a deep pit below the eyes. The lower jaw is short, and
downwardly directed.

The otocysts are much larger. The gut is a little bent downwards in
the middle of its course, and the rectum (r.), except a very short distal
portion, is expanded and tubular. A considerable interval, due to the absorp-
tion of the yolk, now occurs between that structure and the rectum. The
pectorals (p.f.) have increased in size; they are fan-shaped, and their bases are
further forward than before, and have undergone a considerable rotation in the
usual direction. The arrangement of the pigment is somewhat altered. The
earliest pigment bar (p.b.) has been carried backwards with the elongation of the
post-anal region. In front of it are three large pectinate patches along the dorsum,
the most anterior lying above the anus. Similar ventral patches opposite the
two dorsal ones, almost form two anterior bars. The anterior bar noticed in the
larva of four days has disappeared. Large patches, varying in individuals, occur
along the dorsal fin near its margin, the largest being in the anterior region.
Lengthened patches occur along the ventral near its base, principally in the
posterior region. In the specimen figured the dorsal does not extend so far
forward as in the earlier stages shown. The pectorals are pigmented, and embry-
onic fin-rays have appeared in the caudal fin.

In older stages (shown in figures 50 and 51) the prominence of the mid-brain
(m. b.) is still more marked ; the heart is advanced, and the gut is longer and
slightly convoluted; the anus is perforate; and a long urocyst (u.) has appeared
behind the rectum. The pectoral fins are lobate and rayed. The otocysts (ot.)
are larger, and somewhat rectangular and inferiorly concave. They are now close
behind the eyes. There are no oil-globules left in the reduced yolk mass. A
marked angulation of the dorsal fin occurs behind the pectorals.

The post-anal region of the trunk is very attenuated, and the marginal fins
are much expanded.

Black pigment has commenced to appear in the eyes ; and further changes
have taken place in the arrangement of the yellow pigment.

The total length is now 2 '98 mm., the increase being still almost entirely
confined to the post-anal region.

The development of the jaw apparatus is much advanced, the lower jaw (mk.)
projects boldly forward, and is freely moveable. The hyoid and branchial arches
are easily seen, but the latter are not as yet pectinate. The heart (h.) is closed
and perfect. The gut is much lengthened and convoluted, and the liver (/.) is
seen as a lobe-shaped body in the anterior part of the abdomen. There is a

464

Holt — On the Eggs and Larvae of Teleosteans.

conspicuous rectal valve (r.v.). The clavicle (cl.) is conspicuous in front of the very
large fan-shaped pectorals (p-f-), the rotation of which is now complete. The eyes
are black at this stage. The caudal fin has become somewhat lanceolate, and the
dorsal sends down a narrow strip in front of the mid-brain (m. b.).

The post-larval condition (fig. 52) is reached in eight or nine days. There is
no great advance from the last stage, except that the liver (/. ) is larger, and the
gut more convoluted ; whilst the dorsal fin is further expanded in the anterior
region.

No black pigment has appeared except in the eyes, but the yellow pigment has
become somewhat greenish. The total length is from 2*98 to 3*10 mm., there is a
slight increase in the pre-anal length, which is now '96 mm. This is an extremely
hardy species ; with very little attention they were easily reared in small vessels
to the post-larval condition. It is interesting that Professor M'Intosh obtained
two eggs, apparently identical with these, in St. Andrews Bay in the early part of
July of this year, and another occurred on the 30th of that month.

From the characters of the egg and larva I am inclined to think that the parent
species is Solea lutea. This is, of course, mere conjecture, but it is perhaps permis-
sible in view of the many sole-like characters that are met with.

The combination of a cortical layer of yolk segments with numerous small
oil-globules is, as far as I know, confined to the eggs of various species of Solea
and to Raffaele's undetermined species, No. 2, which is probably identical with
this form. I know that Solea lutea breeds about the time these eggs were obtained,
from having found a nearly ripe female of this species in Galway Bay on the 2nd
June. Unfortunately, having much other work on hand, I did not examine its
ova minutely, and can only say that they were very small.

Species III. — Motella-like.
PI. xlvii., fig. 11.

Several specimens of this small pelagic egg were taken in the surface-net in
Blacksod Bay on the 14th and 15th June.

The diameter is ,66mm.; the zona shows no peculiar features; the yolk (g.)
is clear and homogeneous, and there is a single oil-globule (o.g.) in the usual
position, exhibiting a pale greenish-yellow colouration, •14 mm. in diameter.

Of two ova examined one contains an early pigmentless embryo, from the
sides of which faint transverse strise extend outwards over the yolk-sac for a little
distance. In the anterior region the yolk is a little separated from the yolk-sac,
and a faint stellate striation occurs on the upper surface near the oil-globule.

In the other specimen (fig. 11) the embryo is more advanced, having a short

Holt — On the Eggs and Larvce of Teleosteans.

465

free caudal region, and exhibits no striation of the yolk-sac, which may probably
be attributed in the other to ill-health.

Five small black chromatophores occur over the oil-globule, and the yolk-sac
is very sparingly decorated in a similar manner. Small stellate black chromato-
phores occur on the top of the brain, and in a row along each side of the dorsum,
except in the free caudal region, where there is a single median dorsal row.
There is a prominence s. o. ?) on either side of the anterior region of the body,
which perhaps represents a lateral sense organ.

These ova were lost on the 17th June, by the upsetting of my aquaria in a
heavy roll, and 1 never obtained any other specimens.

This form is rather smaller than the egg of Motella mustela, with a rather
larger oil-globule, the colouration of which is distinctive. The pigmentation of
the embryo is also more precocious than in M. mustela, and is differently arranged
(c/. Brook, " The Development of Motella mustela" loc. cit). It agrees with the
egg of M. tricirrata in the arrangement of the pigment, and in the presence of
colouration in oil globule, but differs in size, the egg of this species, according to
Raffaele {op. cit., p. 37), having a diameter of '75 mm., with an oil-globule of
•218 mm.

It seems probable that the present form is a Gadoid, possibly Motella cimbria.

Species IV. — Ctenolabrus rupestris. (?)
PI. xlviii., figs. 23 and 24. PI. xlix., figs. 28-30.

These pelagic ova occurred in the surface-net, in Blacksod Bay on the 15th
June, and in Inver Bay on the 20th and 25th June. They were not abundant.

The egg is spherical, with a diameter of '835 mm., and the zona is thin and
minutely pitted, the yolk translucent and homogeneous. There is no oil-globule.
The perivitelline space is small. The younger stages exhibit no distinctive
characters. Black pigment appears at the time when the free caudal region
becomes noticeable (fig. 23), and is arranged in a row of small chromatophores
along each side of the body, except in the caudal region. A few very minute pig-
ment dots occur at intervals between the outer rows, and there are several
larger chromatophores on the top of the brain.

A specimen obtained on the 20th June exhibited the first formation of the
embryonic shield. Two days later the embryo was far advanced (fig. 24) having
a free caudal region equal to the rest of its length. The body is very slender.
The crystalline lens is fully formed ; the heart beats actively. The otocysts (ot.)
are visible as small ovoidal sacs, with otoliths, remote from the eye. The lateral
row of black chromatophores extends some way along the free caudal region.

I

466

Holt — On the Eggs and Larvae of Teleosteans.

The structure of the notochord {no.), unicolumnar throughout at this stage, is
clearly visible, and there is a broad marginal fin.

I was only successful in hatching one egg of this species, viz. one obtained on
the 25th June. I examined the larva on the 29th June (figs. 28 and 29), when it
appeared to be somewhat older than Agassiz and Whitman's C. adspersus of
twenty-four hours {op. cit., PI. ix.). The total length is 2*855 mm. The pre-anal
length is 1*37 mm., and there is an interval of "62 mm. between the yolk and the
anus; the post-anal length is 1*485 mm.

There are five pairs of lateral sense organs (l.s.o.) as in C. adspersus, of which
the first pair occupies the same position as in the American species, viz. between
the eyes and otocysts. The three remaining pairs, however, lie further back than
in the newly hatched C. adspersus, the second pair lying between the end of the
yolk and the anal region, whilst the last three are placed at equal distances along
the post-anal region. They represent probably some of those more numerous
organs shown by Agassiz and Whitman {op. cit.) in a larva some hours after
hatching (PI. ix., fig. 33). The third and fourth pairs are not quite sym-
metrical.

The greater part of the head projects forward in front of the yolk, terminating
in a blunt snout. There is as yet no mouth. The pineal is easily seen, as are
the precocious nasal sacs {ol.), from which the nasal valves {n. v.) already project
clear of the contour of the head (fig. 30). The cerebellar fold is small. The
otocysts {ot.) are sub-circular and small, and as yet remote from the large unpig-
mented eyes. The pectorals {p.f.) are visible as largish, semicircular folds of
the lateral epiblast about half-way between the snout and anus.

The gut is slightly dilated below the pectoral fins. It runs back as a thick-
walled tube below the notochord to the anal region, at which point it sends down
a solid translucent cord-like limb (r.) almost vertically, to the marginal and imper-
forate anus {a.). The urocyst is not visible.

The notochord {no.) presents the same remarkable structure as in 0. adspersus.
Its anterior third, i. e. the part overlying the yolk, is unicolumnar. At the com-
mencement of the middle-third two cells begin to make their appearance in the
same plane of transverse section, a condition which persists as far back as the
caudal extremity, where, as is frequently the case in larval fishes, the notochord
is irregularly unicolumnar. The cells of the anterior unicolumnar region have not
the same bubble-like structure as is met with in the herring and sprat.

The dorsal marginal fin rises a little behind the otocyst and gradually attains
its greatest height, a little more than that of the body, opposite the anus. The
ventral fin is of the same dimensions as the dorsal, both tapering insensibly into
the short and almost lanceolate embryonic caudal fin. Anteriorly the rectum {r.)
cuts off a pre-anal segment {p. a./.) from the ventral marginal fin, the margin of

Holt — On the Eggs and Larvce of Teleosteans.

467

which is incurved at the anus (a.). Pigment is confined to a double dorsal line of
small black chromatophores, extending from the snout backwards along the
anterior two-thirds of the body.

I think that these eggs and larva may be with little doubt referred to Ctenola-
brns rupestris.

The egg is very little smaller than that of C. adspersus (which measures *85 to
•92 mm.).

The larva is also a little smaller. It will be seen from Agassiz and Whitman's
account [op. cit., p. 18) of C. rupestris, that in the pigment, contour of the larva,
and sense organs, the two species present close resemblances, whilst the notochord,
a feature of importance, has the same peculiar structure in both. That C. rupestris
occurs in the neighbourhood where these ova were obtained is apparent from Day' s
account of their habitat (op. cit., vol. L, p. 265). I myself obtained some young
specimens, but was not so fortunate as to get any sexually mature. Day mentions
a female full of spawn taken at Dublin in June. The American species spawns
from May to July.

These fish seem to be known (in common witli the rest of the Labridse) as
gunners on the Mayo coast.

Species V. — Coris-like.
(PI. xlviii., fig. 16; PL li., figs. 43-45.)

These ova occurred sparingly in the surface-net on the 20th June in Inver
Bay, and on the 7th July at the Bull's Mouth, Achill Island.

The diameter is from -805 mm. to '835 mm., and there is a single colourless oil-
globule of 'lSmm. In its early stages it is not easily distinguished from a
slightly smaller ovum (species VIII.).

The shape is spherical (fig. 16), and the zona (z. r.) presents no feature of
special interest. The peri vitelline space (p. s.) is small, and the yolk (y.) is colour-
less, translucent, and homogeneous.

I have no observations on the development in ovo. The larva emerged on the
23rd from an egg taken on the 20th June.

The larva (fig. 43) is elongated. The total length (including the yolk and oil-
globule) is 2*44 mm., the anus being slightly anterior to median (1*13 mm. from
anterior end of yolk-sac). The flexure of the brain is not so apparent as in most
early larvae (from pelagic eggs), as the elongated yolk (y.), having the oil-globule
(o.g.) at its anterior extremity, projects forward in front of the snout, thus to some
extent preventing the flexure. The perforated region of the gut extends under
the notochord some way behind the yolk, from which the narrow solid rectum (r.)

TRANS. KOY. DUB. SOC, N.S. VOL. IV., PAET VII. 3 U

468

Holt —

On the Eggs and Larvce of Teleosteans.

is separated by a considerable interval. The imperforate anus (a.) is marginal.
There is a small urocyst (u.) in the usual position.

The eyes are of moderate size, unpigmented. The pineal (pn.) is visible; the
cerebellar fold is small. The otocysts (ot.) are small, and somewhat conical
dorsally, and as yet remote from the eye. The pectorals have not appeared.
The dorsal marginal fin commences behind the otocysts, and reaches its greatest
height, about "lSmm., a little behind the anal region. The ventral marginal,
slightly less than the dorsal, is indented towards the anus, as is the pre-anal
segment [p. «./.). The caudal is broad and rounded, and slightly spatulate at
this stage.

The pigment is all black, and is confined to the head and trunk. Largish
stellate chromatophores are distributed sparingly and somewhat irregularly over
the anterior two-thirds of the dorsal surface. A small chromatophore marks the
hind-wall of the urocyst. A little behind the last dorsal, there are two stellate
chromatophores on the ventral edge of the body, and a few small stellate chroma-
tophores occur ventrally and laterally in the extreme caudal region.

A day later the larva (fig. 44) is only 2*38 mm. in total length. This decrease
is due to the partial absorption of the yolk and withdrawal of its anterior
extremity, with the oil- globule, to a point in rear of the fore-brain. The same
cause has operated to increase the downward flexure of the brain (a condition the
reverse of that which is met with in the development of most teleostean larvae),
thus further decreasing the pre-anal length, which is now only 1*01 mm.

The post-anal length has, however, gained "06 mm. The yolk is now bluntly
ovoidal. The gut shows a slight dilatation in the middle of its length (s.), and its
tubular region extends a little further into the rectum. The pectorals (p-f-) have
appeared in the usual position ; they are as yet very small, little more than
prominences of the lateral epiblast. A great deal of the pigment noticed on the
previous day has disappeared ; the head is altogether destitute of it, and the dorsal
chromatophores are fewer in number, whilst some of them aj>pear to have migrated
to the lateral region. The extreme posterior end of the caudal region is slightly
upturned, and the subnotochordal pigment is now dendritic, and extends on to the
marginal fin. Embryonic caudal fin rays have appeared. The heart at this, as
at the previous stage, occupies the usual position, and beats actively. The
structure of the notochord (fig. 45) is somewhat characteristic. The cells
(vacuoles) are large, and sometimes one, sometimes two, or even three occur in the
same plane of transverse section. I was not successful in rearing this species to
an older stage.

The ova and larvae of this form present a remarkable resemblance to those of
Coris j'ulis, Coris giofredi, and Julis turcica, as described and figured by Raffaele
[op. cit., p. 35). Raffaele's ova, however, are smaller, having a diameter of

Holt — On the Eggs and Larvae of Teleosteans.

469

60— 70 mm. , with an oil-globule 16— 18 mm. C. giofredi is regarded by Day
(op. cit., vol. i., p. 269) as a synonym of C. julis. Hoffman (op. cit., p. 11)
describes the ovum of Julis vulgaris as having a diameter of '75 mm., with an oil-
globule of '15 mm., whilst the newly-hatched larva measures 1*77 mm.

Coris julis is the only one of these species that is known to be British, and it
does not seem to have been recorded from Ireland. Centrolabrus, of whose
development nothing is known, appears to be fairly abundant on the west coast.

I am inclined to regard this form as belonging to some member of the
Labridae, and closely allied to Coris. The structure of its notochord presents
considerable resemblance to that of Ctenolabrus. Mullus surmulletus and M. bar-
batus (see Raffaele, op. cit., pp. 20—22) are the only other forms which present
any close resemblance to this in their earlier stages, but, besides differences of
dimensions, there is in their ova a layer of cortical yolk segments, and the anus in
the larva is nearer to the yolk.

Species VI.
(PI. xlviii., fig. 17.)

This species is represented by only a single example, which was taken in the
surface-net in Inver Bay on the 25th June.

The diameter is 1*13 mm., and there is a single oil-globule {o.g.) of -21mm.
The yolk is clear and homogeneous, and there is no colouration of any sort.
Whilst agreeing with another unidentified egg, species VII., in measurements, it
is at once distinguished from it by the large size of the peri vitelline space (p. s.),
and by the entire absence of pigment at a somewhat advanced stage.

My observations deal only with the stage shown in fig. 17. The embryo is
about 1*14 mm. long, of which *30 belongs to the precaudal region. The eyes are
large. I could not make out the otocysts, or the heart. The oil-globule is at the
posterior end of the yolk (g.), which is "66 mm. long and -93 mm. broad.

In the presence of a single oil-globule and a large perivitelline space this egg
approaches that of the pilchard (see Raffaele, op. cit., p. 55, and Cunningham's
later Paper, p. 43), but differs from it in dimensions and in the absence of the
reticulation of the periblast, which is characteristic of clupeoid ova.

Species VII.

(PI. xlviii., fig. 18 ; PL xlix., figs. 25, 25a.)

A few ova, which appeared to belong to the same species, at the same stage of
development, occurred in the surface-nets in Inver Bay on the 25th June.

3 u 2

470

Holt —

On the Eggs and Larvae of Telcosteans.

The diameter varies from 1*07 to 1-13 mm.; and there is a single colourless oil-
globule, "15— '21mm., occupying the usual position at the uppermost pole. The
zona presents no features of special interest. The yolk is clear and homogeneous,
and the perivitelline space is small.

The embryo at this stage (fig. 18) has a short, free caudal region bent up over
the yolk. The otocysts (ot.) have appeared as small round sacs, with a double
outline, in the usual position. The head and eyes are entirely unpigmented, but
a number of minute black pigment dots extend along the trunk on either side of
the notochord from the otocysts to the posterior extremity.

A few larger black stellate chromatophores occur over the oil-globule.

Development appears to be slow, and the species appears to be rather delicate.
None of these eggs hatched, and only one survived till the 29th June.

The egg then lay at the bottom of the vessel, a phenomenon which I have
frequently noticed in advanced ova reared in confinement in this laboratory {e.g.
ova of sprat, gurnard, &c), and one which appears to be in no way attributable
to ill-health, as the larvae emerge and are not appreciably less robust than their
fellows. That it is not due to a change in the specific gravity of the water is
proved by the fact that it occurs even in continually running water of the same
specific gravity. That moribund pelagic eggs should sink is easily intelligible,
but it is hard to understand why this should also happen to perfectly healthy
specimens. It is possibly brought about, in some instances, by the adherence to
the zona of particles of dust, &c, which find their way into the aquaria; but
appears to be a regular feature of development in some species, e.g. T. vipera (cf.
Raffaele, op. cit., p. 30). The embryo (fig. 25) now appears almost ready for
extrusion. The free caudal region is equal to the rest of the body. The eyes
are large, and the otocysts have increased in size, and are vertically elongated,
but as yet remote from the eyes. The pectorals (p-f) have appeared as small
semicircular folds in the usual position. The heart (A.) is large, and beats actively.
The notochord (pi. xlix., fig. 25a) is stout, and its cells show a definite arrangement
into a dorsal and ventral series, the bases to some extent interdigitating, but never
approaching the cuneiform condition. The gut is large and perforate, and shows
two dilatations in the region of the pectoral fins. It is also slightly expanded near
the posterior extremity. The anus appears to lie just behind the yolk. The yolk
is still large, and nearly spherical, the oil-globule (o. g.) now occupying a posterior
position, in a well-marked periblastic pocket. A narrow marginal fin is visible in
the free caudal region of the trunk. The cephalic integument and the whole of the
surface of the yolk-sac (g. s.) is studded with minute tubercles, very conspicuous in
profile.

I have noticed a similar condition in individuals of several species (e.g. Calliony.
mus lyra, Clupea harengus, &c). It is sometimes transitory, as in an early cottoid

Holt — On the Eggs and Larvce of Teleosteans.

471

larva, but it may more usually be looked upon as an indication of approaching
moribundity.

The pigment is remarkable at this stage (fig. 25). It is of two colours : — (1) A
deep bluish-black, perhaps the "nero violacee" of Raffaele, distributed in rounded
chromatophores along the top of the head and dorsum (except the posterior fifth),
and more sparingly in the renal region and over the oil-globule. (2) Bright
reddish-brown, appearing much the same by reflected and transmitted light, very
thickly scattered in small chromatophores all over the head and trunk, except the
posterior fifth, where it is confined to the dorsal and ventral regions; it is less
abundant on the eyes, and there are two small chromatophores, with the black,
over the oil-globule. A little of this reddish pigment also occurs on the part of the
yolk immediately adjacent to the head.

These ova present a close resemblance both in dimensions and pigmentation, to
those of Hemitripterns americanus, identified by Agassiz and Whitman from a
series of young forms obtained in the tow-nets.

The Scorpamidse, to which Hemitripterus belongs, are only represented on the
Irish coast by Scorpcena dactgloptera (a few specimens from deep water),* and
Sebastes norvegicus, which is also rare.

The ova of the former probably resemble those of the Mediterranean species
described by Raffaele, which adhere together in masses and are destitute of oil-
globules, whilst Sebastes is a viviparous form.

Our ova also present some resemblances to those of Sargus and Box, described
by Raffaele {op. cit., p. 23), who remarks that they spawn all the summer. Very
little information as to the breeding season of the British Sparidse is forthcoming,
Day's conjecture {op. cit., vol. i., p. 37) that Pagellus centrodontus spawns in the
winter months being probably due to a misconception of the rate of growth of the
young.

Species VIII.
(PI. xlix., fig. 27; PI. l.j fig. 36.)

This pelagic egg occurred in the surface-net in Blacksod Bay on the 14th, and
in Clew Bay on the 30th June.

It is spherical, with a diameter of *775 mm., and a single colourless oil-globule
of "14 mm.

At the stage shown in fig. 27 the embryo is fairly advanced, but as yet the
free caudal region is short. Small, rather pale yellow chromatophores occur
sparingly over the general surface of the yolk sac, very abundantly over the

* The young of this species were ohtained in considerable numbers, in 80 fathoms, off the Skelligs in
August, during the latter part of the cruise of the " Fingal."

472

Holt — On the Eggs and Larvae of Teleosteans.

oil-globule, and along the sides and on the head of the embryo, but less abundantly
on the dorsum. A few small black chromatophores occur along the sides and on
the head, and at intervals over the yolk-sac.

About twelve hours after hatching (fig. 36) the total length is 2,68mm. The
snout projects boldly in advance of the yolk. The olfactory apparatus (d. ) is
conspicuous ; the eyes are large, but exhibit no black pigment as yet. The
otocysts [of.) small, and inferiorly conical, lie someway behind the eye. The
pectorals {p.f.) have appeared, but are very small. The gut is dilated below the
pectorals, and is tubular, and somewhat broad posteriorly; it projects beyond the
yolk, and terminates blindly below the notochord at a distance of "955 mm. from
the snout. The yolk(?/.) is ovoidal, with postero-ventral oil-globule; the noto-
chord (no.) is somewhat stout, and multi-columnar, with large cells.

The marginal fins are very broad, reaching their maximum a little anterior to
median. The dorsal rises from the top of the mid-brain, and exhibits a remarkable
angulation above the otocysts.

The black pigment has altogether disappeared, whilst the yellow has gained in
brilliancy. It is now a vivid orange by reflected, and brownish yellow by trans-
mitted, light. It covers the whole of the head and trunk in a network of dendritic
chromatophores, except the extreme posterior region, which is devoid of pigment,
and a broad bar about the middle of the post-anal region, which is almost equally
so. The oil globule (o. g.) and the adjacent parts of the ventral fin and yolk-sac,
as well as the anterior region of the yolk-sac, the pectoral fins, and that part of the
dorsal fin which lies below the angulation previously noticed, are also brilliantly
pigmented.

I cannot say much as to the affinities of this form. The dimensions of the
ovum agree well enough with Centropristis hepaticus (c/. Raffaele, op. cit. p. 19),
but the larvae and the two forms present obvious differences.

Species IX.
(PI. xlix., fig. 33.)

On the 13th June off Cleggan Head, near Innishboffin, and off the Bills, and
on the 5th July in Keel Bay, Achill Island, a number of large pelagic ova were
taken in the surface-net. I have referred these to a single species, as, though the
variation in size between the largest and smallest is considerable, between
intermediate specimens it is very slight, and I could see no other character to
distinguish them from each other.

The egg is spherical, with a diameter of 1*49-1 '64 mm., and there is a single
colourless oil-globule of •24-,30 mm. It is thus the largest egg of this series, being
considerably larger than that of the grey gurnard.

Holt — On the Eggs and Larvae of Teleosteans.

473

The zona is thin, the yolk clear and homogeneous, and in the early stages the
perivitelline space is small, and the whole egg is extremely translucent.

The species appears somewhat delicate, as none of the ova hatched, although
several reached a late stage of development. They showed a tendency, at a
comparatively late stage, to sink to the bottom of the vessel, and, after continuing
to develop there for some time, became opaque and died. It would appear that
the larva escapes in a more advanced condition than is usual in pelagic forms.
The yolk is greatly reduced, leaving a very large perivitelline space (fig. 33, p. s.)
before hatching, and the embryo appears older than the escaped larvse of many
forms.

It is characterized, at the later stage examined (fig. 33), by the posterior
position of the oil-globule (o.g.), and the great breadth and peculiar pigmentation
of the marginal fins. The rectum (r. ) lies close against the yolk, behind the oil-
globule, and the imperforate anus (a.) is marginal. The eyes are very large, the mid-
brain (m. b.) dorsally prominent, and the otocysts (ot.) are elongated and inferiorly
concave. The dorsal marginal fin extends forward in front of the fore-brain,
rising abruptly; just behind the anus the trunk has a height of •27mm., the
ventral fin being ^Omni., and the dorsal about equal in height to the body.

Greenish pigment (ochreish-yellow by transmitted light) occurs in small
chromatophores over the yolk-sac, and sparingly on the greater part of the head
and trunk, and along the dorsal and ventral fins about the middle of their width.
There are a few large black stellate chromatophores, with the greenish pigment,
about the oil-globule, and smaller rounded black chromatophores occur over the
yolk-sac, and dorsally and ventrally about the anal region of the trunk. A series
of peculiar pectinate black chromatophores run along the margin of the embryonic
fin backwards from the anal region. I could not see any signs of the pec-
toral fins.

I have no suggestion to offer as to the parent form. It is noteworthy that
these eggs, too conspicuous to escape detection, were only obtained in comparatively
open waters.

NOTE ADDED IN PEESS.

Zabrus maculatus (p. 449). — I had overlooked the late Mr. J. Duncan Matthews's description of the
nest, ova, and larvse of this species. The ova are about 1 mm. in diameter, and the newly-hatched larvae
are 3-75 mm. long ; they are decorated with black and yellow pigment. — (" Eeport Fishery Board, Scotland,
1887," pp. 245-247, pi. xi.)

474

Holt — On the Eggs and Larvce of Teleosteans.

INDEX TO SPECIES.

IDENTIFIED.

PAGE

PAGE

Callionymus lyra, ....

. 442

Nerophis aequoreus, .

. 456

Cepola rubescens, ....

. 446

Nerophis lumbriciformis,

. 456

Clupea harengus, ....

. 456

Pleuronectes cynoglossus, .

. 455

Clupea sprattus, ....

. 455

Pleuronectes microcephalus,

. 453

Crenilabrus melops, ....

. 450

Rhombus lsevis,

. 452

Gobius niger (?), ....

. 441

Scomber scomber,

. 437

Labrus niaculatus, ....

. 449

Sipbonostoma typble, .

. 456

Lepadogaster bimaculatus, .

. 447

Syngnathus acus,

. 456

Macrurus rupestris, ....

. 451

Tracbinus vipera,

. 437

Merluccius vulgaris, ....

. 451

Trigla gurnardus,

. 440

UNIDENTIFIED.

PAGE

PAGE

Species I., Solea (?),

. 457

Species VI., ....

. 469

Species II., Solea lutea (?),

. 460

Species VII., ....

. 469

Species III., Motella-like,

. 464

Species VIII., ....

. 471

Species IV., Ctenolabrus rupestris (?),

. 465

Species IX., ....

. 472

Species V., Coris-like,

. 467

Rbo.ubus l/EVJS.

TABLE

Showing the
Dimensions

(X 40)
of the Ova.

PELAGIC OVA.
Figures 1 to 19.

DEMERSAL OVA
20 to 22.

Whore there is Variation
in tho Ova of a species,
the avorage dimensions
are shown.

Letadooastoi

A-B. — LX*OTH.

CD.— HM

D

ri-ElBONKCTES M1CROCRPI1 ALL'S.

TjLAtMlNrs VIPflA.

KU"WIT* t.MYI*.

PLATE XLVII.

ON" THE EGGS AND LAEV^ OF TELEOSTEANS.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART VII.

[IJ

LETTERING ADOPTED

IN ALL THE FIGURES.

ft. •

anus.

no. . .

. notocbord.

a. o. •

■ air-bladder.

tt. v. •

. nasal valve.

t

0.

blastoderm.

o.g. .

oil-globule, o.g. 1. minute aggregated glo-

0. 0, .

branchial bar.

bules, o. g . 2. larger scattered globules.

v.

. blastodermic rim.

VI. . .

. nasal sac.

Cit •

• clavicle.

op. .

* opercular flap.

. epiblastic ridge connecting pectoral and pelvic

. otocyst.

fins.

p. a.f.

embryonic pre-anal fin.

C. V.

cortical vesicles or segments of yolk.

p. 0. .

pigment bar.

c*. 1 • .

. site of permanent first dorsal tin.

P-J- '

. pectoral fin.

. permanent second dorsal fin.

pl.J. .

pelvic fin.

f

• precepbalic vesicular expansion of dorsal fin.

pineal body.

f.b. .

. fore -brain.

p. S. .

. perivitelline space.

fll. . .

. filaments of attachment process.

p. v.f.

. permanent ventral fin.

g.b. .

. gall-bladder.

r. .

. rectum.

h. . .

heart.

rd. . .

. rod-like attachment-process of zona.

hm.

. byomandibular cartilage.

r.p. .

. rim of central pedicle of attachment.

hp. . .

. hypural lobe of tail.

r. v.

. rectal valve.

hy.. .

. hyoid arcb.

s. . .

. dilatation of gut in region of future stomach .

k. v.

. Kupffer's vesicle.

St. . .

. stratified inner layer of egg-capsule.

1. . .

. liver.

u. .

. urocyst,

1. S. 0. .

. lateral sense organ.

v. m. .

. outer layer of egg-capsule : vitelline mem-

m. .

. moutb.

brane of Brook.

m. b.

. mid-brain.

y. . .

. yolk.

mi. .

. micropyle (closed).

y. s. .

. yolk-sac.

m. o.

. medulla oblongata.

z. r.

. zona radiata.

EXPLANATION OF PLATE XLVII.
Figs. 1 to 12.

\_The pigment, except when otherwise specified, is shown as by reflected light.']

Figure

1. Egg of Lepadogaster bimaculatus, from side.
2, 3. Eggs of the same, from above.

4. Pedicle of attachment, and part of inferior region of zona of the same, more highly magnified.

5. Yolk of newly-hatched larva of the same, from below.

6. Newly -hatched larva of the same, from the side.

7. The same as fig. 6, from above.

8. Optical section of egg-capsule of Trachinus vipera.

9. Egg of Species II. Solea lutea. (?)

10. Egg of the same, less advanced.

11. Egg of Species III.

12. Post-larval Goby, probably Golius niger (by transmitted light).

[2]

Trans. TUhrt>.S.,N.S. Vol. IV.

Plate KLVI1.

PLATE XLVIII.

ON THE EGGS AND L A R ViE OF TEL EOS TEAM" S.

[3j

LETTERING ADOPTED

IN ALL THE FIGURES.

a. . .

. anus.

no. .

. notochord.

a. b.

. air-bladder.

n. v.

. nasal valve.

b. . .

. blastoderm.

o. g.

. oil-globule, o. g. 1. minute aggregated glo-

b.b.. .

. branchial bar.

bules, o. g. 2. larger scattered globules.

b. r. .

. blastodermic rim.

ol. . .

. nasal sac.

el, . .

. clavicle.

op. .

opercular flap.

e. r.

. epiblastic ridge connecting pectoral and pelvic

ot. . .

. otocyst.

fins.

p. a. f. .

. emhryonic pre-anal fin.

0. v.

. cortical vesicles or segments of yolk.

p. b.

. pigment bar.

d. 1. .

. site of permanent first dorsal fin.

P-f- •

. pectoral fin.

d. 2. .

. permanent second dorsal fin.

pl.f. .

. pelvic fin.

/• • •

. precephalic vesicular expansion of dorsal fin.

pn. . .

. pineal body.

/. b. .

. fore-brain.

p. s.

. perivitelline space.

fil. ■ .

filaments of attachment process.

p. v. f. .

. permanent ventral fin.

g.b. .

. gall-bladder.

r. . .

. rectum .

h. . .

. heart.

rd. . .

. rod-like attachment-process of zona.

km.

. hyomandibular cartilage.

r. p.

. rim of central pedicle of attachment.

hp. . .

. hypural lobe of tail.

r. v.

. rectal valve.

hy. . .

. hyoid arch.

s. . .

. dilatation of gut in region of future stomach .

k. v. .

. Kupffer's vesicle.

si. . .

. stratified inner layer of egg-capsule.

1. . .

. liver.

u.

. urocyst.

1. s. o. .

. lateral sense organ.

v. m.

. outer layer of egg-capsule : vitelline mem-

m. . .

mouth.

brane of Brook.

m. b.

. mid-brain.

y. . .

. yolk.

mi. . .

. micropyle (closed).

y. s.

yolk-sac.

m. o.

. medulla oblongata.

z. r.

. zona-radiata.

EXPLANATION OE PLATE XLVIII.
Figs. 13 to 24.

[The pigment, except when otherwise specified, is shown as by reflected light.']

Figure.

13. Ripe unfertilized egg of Rhomlus Icevis.

14. Fei'tilized egg of the same (?), advanced, from the tow-net.

15. Egg of Trachinus vipera, with embryo showing the paired fins (p.f. and pl.f.) connected by a

continuous ridge (c. r.). Pigment and oil-globules omitted.

16. Egg of Species V., early stage.

17. Advanced egg of Species YI.

18. Egg of Species VII.

19. Egg of Pleuronectes microcephalus, with unpigmented embryo.

20. Part of zona of the same, flattened, Z. D. Oc. 2, Cam. luc.

21. The same, seen obliquely, in living egg.

22. Ripe unfertilized egg of Cepola rubescens : dead.

23. Egg of Species IV. Ctenolabrus rupestris. (?)

24. More advanced egg of the same, more highly magnified.

[4]

Trans. R. Dub. S., N.S.Vol. IV.

Plate XLVIII

PLATE XLIX.

ON THE EGGS AND LARVAE OF TELEOSTEANS.

TRANS. EOY. DUB. SOC, N.S. VOL. IV., PART VII.

[5]

LETTERING ADOPTED

IN ALL THE FIGURES.

a. . anus.

a. b. . . air-bladder.

b. . blastoderm.
b.b. . . branchial bar.

b. r. . . blastodermic rim.

el. . . clavicle.

e.r. . . epiblastieridge connecting pectoral and pelvic
fins.

e. v. . . cortical vesicles or segments of yolk.
d. 1 . . . site of permanent first dorsal fin.

d. 2. . . permanent second dorsal fin.

f. . . . precephalic vesicular expansion of dorsal fin.
/. b. . . fore-brain.

Jil. . . . filaments of attachment process.

g. b. . . gall-bladder.

h. . . . heart.

km. . . hyomandibular cartilage.

hp. . . . hypural lobe of tail.

hy. . . . hyoid arch.

h. v. . . Kupffer's vesicle.

1. . . liver.

/. s.o. . . lateral sense organ.

m. . . . mouth.

m.b. . . mid-brain.

mi. . . . micropyle (closed).

in. o. . . medulla oblongata.

no. .
n. v.

0. g.

01. .
op.
ot. .
p. a.f.
p. b.

Pf-
pl.f.
pn. .
p. s.
p. v.f.
r. .
rd. .
r. p.

st. .
u. .
v. m.

V- ■

y. s.
z. r.

o.g. 1. minute aggregated glo-
. g. 2. larger scattered globules.

notochord.
nasal valve,
oil- globule.

bules. i
nasal sac.
opercular flap,
otocyst.

embryonic pre-anal fin.
pigment bar.
pectoral fin.
pelvic fin.
pineal body,
perivitelline space,
permanent ventral fin.
rectum.

rod-like attachment-process of zona,
rim of central pedicle of attachment,
rectal valve.

dilatation of gut in region of future stomach,
stratified inner layer of egg-capsule,
urocyst,

outer layer of egg-capsule : vitelline mem-
brane of Brook,
yolk,
yolk-sac.
zona radiata.

EXPLANATION OE PLATE XLIX.
Figs. 25 to 33.

\_The pigment, except when otherwise specified, is shoivn as by reflected light. .]

Figure

25. Egg of Species VII., four days older than fig. 18, pi. n.
25«. Part of notochord of same, more highly magnified.

26. Egg of Species I. Solea. (?)

27. Egg of Species VIII.

28, 29. Larva of Species IV. Ctenolabrns rupestris. (?) Some time after hatching. Ventral and profile
view.

30. Cephalic region of same, more highly magnified.

31. Egg of Trachinus vipera, early stage, x 40.

32. Advanced stage of same, more highly magnified.

33. Egg of Species IX. (by transmitted light).

[6]

Trans. R.Dub. S.. K.S.Vol. IV.

Plate XLIX.

W L.Holt, M

F. Huth.Lith1 Edm1

PLATE L.

ON THE EGGS AND LA RViE OE TELEOSTEANS.

LETTERING ADOPTED

IN ALL THE FIGURES.

a.

anus.

no. .

. notochord.

a. b.

. air-bladder.

n. v.

. nasal valve.

b. . .

. blastoderm.

o. g. .

. oil-globule, o. g. 1. minute aggregated glo-

b.b.. .

. branchial bar.

bules, o. g. 2. larger scattered globules.

b. r. .

. blastodermic rim.

ol. . .

. nasal sac.

el., . .

clavicle.

op. .

opercular flap.

c. r.

. cpiblastic ridge connecting pectoral and pelvic

ot. . .

. otocyst.

fins.

p. a.f. .

embryonic pre-anal fin.

c. v.

. cortical vesicles or segments of yolk.

p. b.

. pigment bar.

d. 1. .

. site of permanent first dorsal fin.

P-f. •

pectoral fin.

d. 2. .

. permanent second dorsal fin.

pl.f. ■

. pelvic fin.

/• • •

precephalic vesicular expansion of dorsal fin.

pn. .

. pineal body.

/• b. .

. fore-brain.

p. s.

. perivitelline space.

fil- ■ .

filaments of attachment process.

p. v.f. .

. permanent ventral fin.

g.b. .

. gall-bladder.

r.

. rectum.

h. . .

heart.

rd. . .

. rod-like attachment-process of zona.

hm.

. hyomandibular cartilage.

r. p.

. rim of central pedicle of attachment.

hp. . .

. hypuial lobe of tail.

r. v.

. rectal valve.

hy. . .

. byoid arch.

s. . .

. dilatation of gut in region of future stomach.

k. v.

. Kupffer's vesicle.

St. . .

. stratified inner layer of egg-capsule.

1. . .

. liver.

u. . .

. urocyst.

1. S. 0. .

. lateral sense organ.

v. m.

. outer layer of egg-capsule : vitelline mem-

m.

mouth.

brane of Brook.

m. b.

mid-brain.

y. . .

. yolk.

mi. .

. micropyle (closed).

y. s.

yolk-sac.

m. o.

medulla oblongata.

z. r.

. zona-radiata.

EXPLANATION OE PLATE L.
Figs. 34 to 39.

[The pigment, except when otherwise specified, is shown as by reflected light.~\
Figure.

34. Larva of Species I. Solea. (?) Profile view.
$5. Dorsal view of anterior region of the same.

36. Larva of Species VIII., about twelve hours after hatching

37. Larva of Tracliinus vipera, shortly after hatching.

38. The same, early post-larval stage.

39. Larva of Pleuronectes microcephalics (by transmitted light).

[8]

EW. L.Holt, del.

F Huth.Lithf Kdmr

4

PLATE LI.

ON THE EGGS AND L AR ViE OF TELEOSTEANS.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART VII.

[9]

LETTERING ADOPTED

IN ALL THE FIGURES.

a. . .

. anus.

no. . .

. notochord.

a. b.

. air-bladder.

n. v. .

. nasal valve.

b. . .

. blastoderm.

o.g. .

. oil-globule, o.g.l. minute aggregated glo-

b.b. .

. branchial bar.

bules, o. g. 2. larger scattered globules.

b. r. .

. blastodermic rim.

ol. . .

. nasal sac.

el.

. clavicle.

op.

. opercular flap.

c. r.

. epiblastic ridge connecting pectoral and pelvic

ot. . .

. otocyst.

fins.

p. a.f.

. embryonic pre-anal fin.

e. v.

. cortical vesicles or segments of yolk.

p. b. .

. pigment bar.

d. 1. .

. site of permanent first dorsal fin.

P-f- •

. pectoral fin.

d.2. .

. permanent second dorsal fin.

pl.f. .

. pelvic fin.

/• • •

. precephalic vesicular expansion of dorsal fin.

pn. . .

. pineal body.

/.*■ •

. fore-brain.

p. s. .

. perivitelline space.

fil. ■ .

. filaments of attachment process.

p. v.f.

. permanent ventral fin.

g.b. .

. gall-bladder.

r. . .

. rectum.

h. . .

. heart.

rd. . .

. rod-like attachment-process of zona.

km.

. hyomandibular cartilage.

r.p. .

. rim of central pedicle of attachment.

hp. . .

. hypural lobe of tail.

r. v.

. rectal valve.

hy. . .

. hyoid arch.

s. . .

. dilatation of gut in region of future stomach.

k. v.

. Kupffer's vesicle.

St. . .

. stratified inner layer of egg-capsule.

1. . .

. liver.

u. .

. urocyst,

1. S. 0. .

. lateral sense organ.

'V. m. .

. outer layer of egg-capsule : vitelline mem-

m. .

. mouth.

brane of Brook.

m. b.

. mid-brain.

y. . .

. yolk.

mi. . .

. mieropyle (closed).

y. s. .

. yolk-sac.

m. o.

. medulla oblongata.

z. r.

. zona radiata.

EXPLANATION OF PLATE LI.
Figs. 40 to 45.

[The pigment, except when otherwise specified, is shown as by reflected light.']

Figure

40, 41. Newly-hatched larva of Callionymus lyra. Ventral and profile views.

42. Larva- of the same, ahout twelve hours old.

43. Larva of Species V., shortly after hatching. 4

44. The same larva, one day older.

45. Part of notochord of the same, more highly magnified.

[10]

Trail s . R . D ub . S . , N . S . Vol . IV.

Plate LI.

E.W.L Holt del

F. Huth, Lithr Edk?

PLATE LI I.

ON THE EGGS AND L A R V OF TELEOSTEANS.

[HI

LETTERING ADOPTED IN ALL THE FIGURES.

&. .

anus.

no. .

ti otnp Vi nvA
. M i 1 1 i 1 1 .

a. b.

air-bladder.

H. v.

Tifltsnl vnlvp
. mm 1 1 i 'ii i 1 .

b. . .

. blastoderm.

. o. g. .

m 1 _ (r 1 nrii 1 1 P P fi 1 mimifp o rpfrroffntort rr 1 A -

. un giuumo. v. y. i. iiiinuib ti t y<neu giu

b. b. . .

branchial bar.

bules. o. g. 2. larger scattered globules.

b. r.

■ blastode nine rim.

ol.

TIHCll OOP

• M.l .1 I baO.

el., . .

• clavicle

op. .

upeiUUlal Hap.

c. t. .

. epiblastic ridge connecting pectoral and pelvic

ot.

fins.

p. a. f. .

pmlivvnnin YiTp-nnfll fin

. 1 1 M 1 ' 1 \ 'III |M l "MIKII LL11.

c v. .

povflpnl vpsiplpa nv spcrmpntq Af T7p.Ur
. vui ULat v coiuiuo \JL BogulOilto \Ji VUllfc.

• pij^meiii uai .

d. 1.

site fit llPi'nn ti pn f" fivct flni'Qfi! fin

M f

P- J-

Yippr/wnl Tin
• [II ' I'M'll 1111.

d. 2.

TlPTm.inpnf' OPPPnP /Ipvenl fin
• j1 1 Ml 1 III Ml. faULUUU. UUlbcll 1111.

pi. J.

. pelvic fin.

j m ■

» precepbalic vesicular expansion of dorsal fin.

pvt.

pineal body.

J * v» •

• fore-brain.

F' *• 1

perivitelline space.

fil. . .

filaments of attaebment process.

v. v. f. .

permanent ventral fin.

g.b. .

. gall-bladder.

r. . .

. rectum.

h. . .

. heart.

rd. . .

. rod-like attachment-process of zona.

Km.

. byomandibular cartilage.

r. p.

. rim of central pedicle of attachment.

hp. . .

. bypural lobe of tail.

r. v.

. rectal valve.

hy. . .

. hyoid arch.

s.

. dilatation of gut in region of future stomach.

k. v. .

. Kupffer's vesicle.

St. . .

. stratified inner layer of egg-capsule.

1. . .

. liver.

u.

urocyst.

1. s. o. .

. lateral sense organ.

v. m.

. outer layer of egg-capsule : vitelline mem-

m. . .

. mouth.

brane of Brook.

m. b.

. mid-brain.

y. . "*

. yolk.

mi. . .

. micropyle (closed).

y. s.

. yolk-sac.

m. o.

. medulla oblongata.

z. r. .

. zona-radiata.

EXPLANATION OE PLATE LII.
Figs. 46 to 52.

[The pigment, except when otherwise specified, is shown as by reflected light.']

Figure.

46. Newly-hatched larva of Species II. Solea lutea. (?) Ventral view.

47. Larva of the same, about one day old. Profile view.

48. Larva of the same, two days old.

49. Larva of the same, four days old (by transmitted light).

50. Larva of the same, about six or seven days old (by transmitted light).

51. Anterior region of larva about six days old, more highly magnified.

52. Early post larval stage of the same, eight or nine days old.

[12]

Trans. R.Dtrt>. S.,N S.Vol. IV.

FHutli.Lith1 Edinr

[ 475 ]

VIII.

THE CONSTRUCTION OF TELESCOPIC OBJECT-GLASSES FOR THE INTER-
NATIONAL PHOTOGRAPHIC SURVEY OF THE HEAVENS. By SIR
HOWARD GrRUBB, M.A.I., F.R.S., Hon. Sec. Royal Dublin Society.

[Read November 19, 1890.

In the construction of telescopic objectives for visual use, it is necessary to satisfy
two conditions only, assuming, of course, that the quality of the material and
the workmanship of the surfaces be perfect. These two conditions are, that the
chromatic and spherical aberrations be corrected as nearly as possible. In the con-
struction of objectives suitable for photography, it is necessary to satisfy a third
condition, viz. freedom from coma in the lateral pencils, in order to obtain as
perfect a field as possible.

If the lateral images of an ordinary telescopic objective be examined, it will be
found that at a very small distance from the centre of the
field of view, say 20' or 30', a very sensible coma is appa-
rent : this coma is toward the axis, and gives the images
the appearance shown in fig. 1. Owing to the small field
usually employed, or necessary to be employed, in astro-
nomical telescopes, this coma is rarely seen, but observers
are quite familiar with the appearance of a star, when the
objective is out of adjustment, and requires alteration
to place its axis coincident with the axis of the tube. The appearance in that
case is the same as that mentioned above, for the images that the observer then
sees in the centre are really due to lateral pencils ; and it is by the position of this
coma that the observer determines the direction in which the necessary adjust-
ment must be made, in order to utilize the central pencil, and get the best results.
In determining the best form to be given to these objectives, it was necessary to
keep in view the ultimate purpose for which the photographs obtained by them
were intended. Some forms of objectives give a very widely-spread coma,
with a very distinct nucleus in the lateral images, and photographs taken with
such objectives are sometimes very deceptive. For, if no large stars be upon

TKANS. EOT. DUB. SOC, N.S. VOL. IV., PABT VIII. 3 U

476

Grubb — On the Construction of Telescopic Object- Glasses.

the plate, the images appear very perfect for a considerable distance from the
centre, the fact being that the coma is so widely spread, and consequently weak
in intensity, that it is invisible in the case of the smaller stars. On consideration,
however, it will be seen that such images would be useless for the purpose
required, viz. accurate measurements. The image of a small star would only be
that of its nucleus, while the image of a large star would include the coma which
extends in this case not symmetrically on each side of the nucleus, but almost
altogether on the side toward the centre ; consequently the distances of all large
stars from a central point would measure too small, as compared with those of
stars of less magnitude.

It is not possible to obtain absolutely round images of stars anywhere on a
plate, except at or near the centre ; but it is evidently
necessary that whatever departure from a perfect circle
the image may be, it must be symmetrical on each side
of a tangential, as well as of a radial line cutting its
centre (see fig. 2). That is to say, if C be the centre
of the field, the image of the star must be symmetrical
on both sides of the lines AB, CD. This, then, is the

Fig. 2.

condition that must be satisfied in photographic objectives, as well as those
mentioned before as necessary to be satisfied in the case of visual objectives,
viz. freedom from chromatic and spherical aberrations.

In addition to the conditions above mentioned which it is necessary should be
satisfied in the case of all photographic objectives, one more condition insisted on
in the case of the objectives for the International Survey was, that all objectives
should be within a very small percentage of the same focal length.

A little consideration will show that the imposing of these two additional
conditions increased in a very high degree the labour in the construction of the
objectives. It is convenient in considering the various alterations in the form of
objectives to imagine the glass flexible, and capable of being bent out of its
normal state to any other required form. Taking the form of the ordinary visual
objective to start with, which with the more usually used qualities of glass is

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

almost a bi-convex crown with a plano-concave flint fitting as in fig. 3, it is
necessary, in order to eliminate the coma, that the crown be either bent forwards
on edge as in fig. 4, or the flint bent backwards as in fig. 5. In other words,

Grubb — On the Construction of Telescopic Object- Glasses. 477

that the two lenses be of such a form as would touch in centre if placed close
together. By continuing the bending a point is reached at which the coma is
cured ; if we go further we obtain coma outwards. When the proper balance of
coma is obtained we have an objective of approximately the form shown in fig. 6.*
But, unfortunately, whichever course we adopt, either that of bending forward
the crown or bending backward the flint, the correction for spherical aberration
is destroyed. Bending forward the crown renders it (the crown) a lens of greater
positive spherical aberration, and bending back the flint renders it (the flint) a
lens of less negative aberration. In either case the spherical aberration of the
whole is rendered strongly positive.

Again, in order to correct the objective for coincidence of the active chemical
rays, it is necessary either to increase the power of the crown, or reduce the
power of the flint; and this again introduces more positive spherical aberration
into the objective, the result being a lens, corrected for chemical rays, corrected
for coma, but under-corrected by a considerable quantity for spherical aberration.
In an ordinary visual objective if the spherical aberration be found to be
under-corrected, a modification of the form of either of the components should be
made in order to correct this, but in this case all four curves are already fixed
in order to fulfil the three conditions of focal length, chromatic aberration, and
spherical aberration, consequently there is no latitude for further alteration. The
total power of the combination is already fixed in order to fulfil the condition of
focal length. The proportion of the power of crown to flint is already a fixed
quantity in order that the chemical rays be united. If therefore the total power of
the combination, and the proportional power of crown to flint be fixed, the actual
powers of crown and flint are also fixed quantities. Lastly, the proportion of
power on each surface of crown and flint, i. e. the form of the lens, is either fixed,
or variable only in such directions as will not sensibly alter the correction for
spherical aberration of the whole combination, that is to say, the correction for
coma may be made as before stated, either by bending forward the edge of the
crown, or bending back the edge of the flint, or by a combination of both, but in
any case the correction for spherical aberration is reduced.

As there is no possibility of altering the curves of any surface of the objective
without destroying the correction for one or other of the foregoing, the only
possibility of correcting the spherical aberration is by figuring the surfaces to a
form other than that of a sphere, and this is the course I was obliged to adopt
when using this particular form of objective.

* The same effect on coma can also be obtained by separating the crown and flint, but in most cases the
amount of separation required is excessive, and introduces more positive spherical aberration than the other
method.

478

Grubb — On the Construction of Telescopic Object- Glasses.

During the course of my investigations on these objectives, I worked out
another form which gives very admirable results, and without as much or indeed
any sensible forcing of the curves out of the spherical form.
This objective is shown in fig. 7. In this form the flint is
the outermost, and receives the parallel rays ; the two inside
curves are, as in the other form, so proportioned that they Fig. 7.

would touch in the centre; and the outside of the crown is nearly piano. This lens
when corrected for coincidence of the chemical rays and for coma, is very nearly
correct for sj)herical aberration also, and therefore its preparation is less trouble-
some than the form first described. If the inside curves were made to coincide
there would be coma, but its direction would be the reverse of that given by the
first described form, viz. it would be from, instead of towards, the centre of the field
of view. In the vicinity of smoky cities this form might be objected to. Having
the flint glass exposed to the influence of the air, it is more likely to be injured
than if the crown were outermost. This form corrected for visual rays would make
an admirable objective for transit instruments, or in any case where a large field
is required.

The testing and correcting of these photographic objectives is much more
troublesome than that of visual objectives. In visual objectives, the judging
as to the perfection of the chromatic and spherical aberrations is altogether a
matter of experience of the eye of the observer. A very few moments of favour-
able observation on a star or small point of light is sufficient to enable the
experienced eye to judge of the fault to be corrected in the case of visual
objectives, but in the case of the photographic objective no visual observations
are of any use whatever, except that the state of the chromatic aberration
can be roughly estimated by observing through various coloured glasses,
or better still, through a film of ammonio-oxide, or ammonio-nitrate of copper ;
but the amount of outstanding colour is so great that no judgment can be
formed of the state of the spherical aberration, and for the final tests photographs
must be taken at every step of the process. When it is remembered that a clear
sky and the utmost perfection of driving mechanism in the most perfect order is
necessary in order to obtain these photographs, it can easily be imagined how
very great are the difficulties in the preparation of the object-glasses.

Every step in the final corrections and final adjustments require a photograph
to be taken, and consequently some of the simpler adjustments which are generally
made within the space of an hour or so in the case of visual objectives, require in
the case of photographic objectives a series of photographs to be taken, some-
times in consequence of broken weather, extending over several days, or even
weeks.

As I have mentioned before, the final and crucial test for these object-glasses

Grubb — On the Construction of Telescopic Object- Glasses. 479

is that of its performance on celestial objects. Many trials and experiments were
made to get satisfactory artificial stars for testing these glasses, but although these
are amply sufficient and perfectly satisfactory for testing visual objectives, they
have not been found of so much use in the testing of photographic objectives.
They were used largely in the earlier process, and in case of bad weather were a
considerable help in forwarding the work more quickly than could have been done
were it necessary always to wait for fine nights. But for final tests nothing but
the natural star was perfectly satisfactory. During the testing of seven of these
objectives a considerable amount of experience in celestial photography has been
obtained, and I take occasion to remark that my experience does not tally exactly
with that of Dr. Gill respecting the influence of atmospheric disturbance on the
photographed images of the stars. He has stated that, with an exposure of over
five minutes, as perfect, or very nearly as perfect, star-plates can be obtained on
nights when the atmosphere is highly disturbed as on those when the air is
perfectly steady. My experience goes to corroborate this so far as the large stars
are concerned, but not as respects the small stars, and I think this is easily
explained. Bright stars with long exposures imprint images on the photographic
plate of considerable diameter. It is not necessary to discuss whether this increase
of diameter is due to some form of halation, or chemical action ; the fact remains
that the longer the exposure the larger the image printed on the plate by any star.
Consequently it is easy to understand that atmospheric disturbance which causes,
as all observers know, a flickering and wavering, and general unsteadiness of the
image, will have little or no effect on the photographic image in the brighter stars,
because the amount of that wavering will always be far less than, and well con-
tained within, the area of the surface which these brighter stars occupy on the
plate ; but, in the case of small stars, and more particularly with very small stars,
it is impossible to conceive that a point of light which would under favourable
circumstances imprint itself as a speck of not more than f^th to perhaps T 75-^th of
an inch in diameter would produce equally perfect impressions on the plate if,
during exposure, it wavered about over an area considerably more than its own
diameter, and this is, as all observers know, the case on nights of bad definition.
I was certainly surprised to find the very excellent images that were obtained of
the larger and even moderate-sized stars on nights of exceedingly bad definition,
but my experience shows that the images of smaller stars suffer very decidedly
from the effect of atmospheric disturbance.

It may be interesting to record here that trials of a form of objective suitable
for use either for a visual or a photographic purpose, proposed by Sir George G.
Stokes have proved satisfactory. By separating the lenses of an ordinary visual
objective, such as fig. 3, a point will be reached when the necessary correction for
photographic rays will be obtained, but the spherical aberrations will then be

TEANS. EOT. DUB. SOC, N.S. VOL. IV., PAET VIII. 3 X

480

Grubb — On the Construction of Telescopic Object- Glasses.

strongly positive. Sir George Stokes' suggestion is to grind the crown rather more
convex on the inside than the outside, leaving the power of both crown and flint as
before. The result of this will be to introduce a little positive spherical aberration.
Let that be corrected by figuring the lens. When required for photographic use
the lenses are separated as far as necessary to correct for photographic rays, and
the crown lens is then reversed. The crown is now in a position of lower
(positive) spherical aberration, and this balances the amount of aberration intro-
duced by the separation. This has been successfully tried with small-sized
objectives.

[ 481 ]

IX.

LUNAR RADIANT HEAT, MEASURED AT BIRR CASTLE OBSERVATORY,
DURING THE TOTAL ECLIPSE OE JANUARY 28, 1888. By OTTO BOED-
DICEER, Ph.D. With an Introduction by THE EARL OE ROSSE, K.P., LL.D.,
F.R.S., &c, President of the Royal Dublin Society. Plates LIIL, LIV., LV.

[Read February 18, 1891.]

Introduction.

Some years ago it was suggested that it would be desirable to turn the large
Reflectors at Parsonstown, armed with the thermopile, upon the moon, with the
view of detecting, and, if possible, measuring its radiant heat. Several attempts
to do so had been made elsewhere, but without encouraging results. Melloni had
employed a lens of three feet aperture of imperfect quality, but sufficiently good
for the purpose. Owing, however, to the large absorption of heat by glass he
obtained no very certain indications, his pile could not have received any of the
less refrangible heat rays through the glass, but it appeared quite possible that
with a speculum of equal aperture far more decided and really interesting and
instructive results might be arrived at. Accordingly, I procured a thermopile of
four elements, with surface of face half an inch square, from Messrs. Elliott, fixed
it in the principal focus of a concave reflector of three and a-half inches aperture
and three inches focus, and placed the whole in my three-foot telescope, the con-
cave mirror being situated at the focus, and directed towards the speculum.
Thus the whole of the Moon's radiant heat (and light) which entered the three-
foot tube was concentrated upon a spot of one-third of an inch in diameter, on
the centre of the face of the pile. At first the indications were very uncertain.
They were so masked by accidental disturbances that they could be detected with
certainty only by taking the mean of a series of readings with the telescope
directed towards the Moon, and comparing it with that of a series with the
telescope. turned away from the Moon. I then procured a second pile from Messrs.
Elliott, fitted it and a similar concave reflector close beside the first, and placed
both piles, but with poles in reversed position, in the same circuit with the
galvanometer. Thus, by turning the telescope, so that the Moon's image fell

TRANS. ROY. DUB. SOC, N.S. YOL. IV., PART IX. 3 Y

482

Boeddicker — On Lunar Radiant Heat.

alternately upon each pile, the effect sought for was nearly doubled, while
extraneous disturbing effects tended generally to counteract one another. Still
the needle was at all times more or less, and often very unsteady, though by
taking means of a long series of alternate readings it was found possible, not
only to demonstrate the existence of a very appreciable amount of radiation, but
even roughly to estimate its variation with the phase and form, a curve generally
representing that variation. The results were published in the Proceedings of the
Royal Society, No. 112, 1869.

During the following season the experiments were pursued with modified
apparatus ; and, under the idea that the annoying disturbances of the needle still
subsisting were largely due to an inequality of power between the two piles,
these were replaced by thermocouples of home manufacture, selected out of a
number, so as to be as nearly alike as possible.* They are described in the
Proceedings of the Royal Society, No. 122, 1870; the results were published in
the Proceedings, No. 123, 1870. In addition to another heat-curve, which, not-
withstanding the modifications of the piles, does not give a more precise determi-
nation, I was able by the interposition of a sheet of glass to show in the above
communication that the Moon's heat differed materially from the Sun's in that it
contained a much larger proportion of rays of low refrangibility. From the very
rapid diminution of the heat towards New Moon it was probable that at that phase
the remaining heat would be scarcely if at all appreciable, and from these two
facts I concluded that the heat which I had been attempting to measure was heat
received by the Moon from the Sun, but only re-radiated after part of it had been
absorbed by the lunar surface, and then emitted as dark rays of heat. At the
same time, so far as could be gathered from these rough determinations the
maximum of heat did not take place as might, perhaps, have been expected to an
appreciable degree after the maximum of light, that is after Full Moon. Some
rough determinations of the proportion between lunar and solar radiation were
also made.

At this stage Dr. Copeland, who had taken up the post of Astronomical
Assistant in my Observatory, began to devote much labour and patience to the
investigation, using the same apparatus, only refitted and adjusted, as I had
employed in the season 1869-70. He formed a more concordant series of mean
results, and having fully reduced them, and having by long series of observations
at largely varying altitudes obtained a curve for the absorption of heat by our
atmosphere, he was able to produce a more reliable phase-curve for heat.

The determinations of the quality of the radiation by interposition of a sheet

* The thermopiles of hismuth, and an alloy of 12 hismuth to 1 tin were replaced about three and a-half
years ago by thermopiles of iron and German silver, the wire of commerce being used in each case.

Boeddicker — On Lunar Radiant Heat.

483

of glass were repeated, and they confirmed, as far as possible, the former results.
The phase-curve strengthened the previous impression that no appreciable interval
existed between the time of maximum of light and of the maximum of heat ;
on the contrary, from some unexplained cause the maximum of heat seemed
to occur somewhat before Full Moon.

Dr. Copeland's determinations, together with his discussion of them, were
published in the Philosophical Transactions for 1873.

The striking result having been arrived at that the maximum of heat did not
lag behind Full Moon, it appeared desirable to proceed a step further, and as a
more rigid test to try how far the minimum of heat, which presumably existed
during the progress of a lunar eclipse coincided with, or came later than the
middle of that eclipse. Every visible lunar eclipse was eagerly waited for.
The first occasion on which we were able to obtain a glimpse of the Moon during an
eclipse was on November 14, 1872. The eclipse was only partial. The Moon was
at a low and a diminishing altitude, and clouds interfered much. The heat
radiation was, however, observed rapidly to decline during its progress, apparently
as much as the light.

On October 4th, 1884, the next favourable opportunity occurred.* Dr.
Boeddicker. was on the spot with the apparatus in position from the commence-
ment of the penumbra until forty minutes after the last contact with the
penumbra. Clouds intervened until twenty-three minutes before totality, when
the sky became perfectly clear, and remained so until the end of the observations.
The heat as before diminished, and increased again nearly proportionally to the
light, becoming inappreciable on reaching the limits of totality. The minimum
of heat apparently fell later than that of illumination. But the most remarkable
thing was that while during the short interval between the first contact with the
penumbra and the commencement of total phase all appreciable radiation vanished,
between the end of total phase and the last contact with the penumbra, and even
forty minutes later the heat had not returned to the standard for Full Moon, being
deficient by about twelve per cent. This we failed to explain, where we might
expect to do so, by any derangement of the apparatus, nor could we trace it to
any physical cause. The above observations were published in these Transactions
for 1885 (vol. iii., series 2).

The next opportunity, an exceptionally favourable one, occurred on January
28, 1888. The sky was not obscured at all during the whole progress of the
eclipse, and the same anomaly of the heat not returning to its standard value, even
1 hour 40 minutes after the last contact with the penumbra was observed. Also

* A total eclipse had meanwhile taken place on August 23, 1877, but owing to many interruptions
from clouds, and the low altitude of the Moon, no advance was made. See Copernicus, vol. i., p. 22.

3 Y 2

484

Boeddicker — - On Lunar Radiant Heat.

the radiation which we began to measure 1 hour 5 minutes before the first con-
tact with the penumbra seemed to begin to decrease almost immediately ; and
even if the first observation be excluded, yet the decrease of heat seemed to begin
as early as 15 minutes before the commencement of the eclipse. These results
would appear to be particularly interesting as suggesting a terrestrial atmosphere
much more extensive than it has generally been supposed to be which intercepts
the Sun's rays of heat long before any part of the Moon has reached the Earth's
shadow. We would much desire another opportunity for attacking the subject.
As, however, it is exceedingly unlikely that the possibility of measuring the heat
during an eclipse under similarly favourable meteorological conditions will soon
recur here, and as it does not seem profitable to spend more time in getting a
slightly more accurate phase-curve, it seems desirable that the present communica-
tion should close the series. If we pursue the subject of radiant heat further, it
will be by making a new departure with apparatus modified so as if possible to
combine greater sensibility with greater freedom from extraneous influences,
varying also the methods, and extending the subjects and objects of investigation.

Dr. Boeddicker has devoted a great amount of time and labour to the fullest
reductions, and to the formation of the theoretical curve for the Moon's light,
possibly more than was justified by the probable errors of the observations, but as
the occasion was quite an exceptional one it appeared best to leave nothing
undone to get the utmost out of the night's work.

Lunar Radiant Heat.

I. — The Observations of 1888 and their Reduction.

1. As mentioned by Lord Rosse in his introduction to this Paper, my observa-
tions in 1884 — the first really successful series of heat-observations during an
eclipse — showed the striking anomaly, that 38 minutes after the last contact with
the penumbra, the lunar heat still fell short of the Full Moon value by 13 -2 %•
Though I never doubted the reality of this very unexpected result, yet others did
so ; and the fact that the value for the lunar heat corresponding to Full Moon
could not be obtained on the same night before the beginning of the eclipse (the
Moon rose eclipsed, and clouds intervened till 23 minutes before the beginning of
the total phase), but had to be deduced from extra-eclipse observations, gave a
certain strength to these doubts. For it is well known how the state of the
atmosphere affects these observations, and renders conclusions from one night to
another difficult and uncertain. It became, therefore, most desirable to carry
these observations on during an eclipse which could be watched at Birr Castle

Boeddicker — On Lunar Radiant Heat.

485

Observatory during the whole of its course. Such an opportunity occurred on the
28th January, 1888, and was again exceptionally favoured by the weather, the
sky being perfectly clear (without any wind) the whole night through.

2. The mode of observing was essentially the same as in 1884. The
thermopiles of 1888, however — single thermic junctions — had been newly made
by Lord Rosse for the occasion, and were very considerably more sensitive than
the former ones. Consequently, one important alteration could be made, namely,
each pile was exposed for 30 seconds sidereal time only (against one minute in
1884); or, in other words, the galvanometer was read off every half minute, as
this time sufficed to obtain the maximum deflection. The labour of observing
was divided in such a way that Lord Rosse watched the thermopiles, and the
driving clock of the telescope, while I took all the readings of the galvanometer.
The alternate exposing of the thermopiles, which is readily done by simply
raising and lowering the telescope (of three-feet aperture) was done by an
assistant, the signal for it being given by me every 30 seconds by means of an
electric bell. The reading off of the galvanometer was carried on as far as possible
continuously during the whole of the eclipse. Some interruptions could, however,
not be avoided, and may be here at once enumerated.

3. Preliminary observations were taken from 3h 20"2m to 3h 25'2m, and from
4h 6"7m to 4h 1 1 *7m sidereal time. The continuous series commenced at 4h 16*7m.
No observations were obtained from : — 4h 37"2m to 4h 39 '2m (the zero point of the
galvanometer had to be changed) ; 5b 6"2m to 7'7m (three readings were missed, the
signal not being understood by the assistant at the telescope); 5h 14,2m to 20"2m
(the clock-sector had to be wound back); 5h 38*2m to 38 "7m (one reading was
missed); 5h 48'7ra to 6h 0-2m ; 6h 15-7m to 22*7m ; 6h 25-7m to 45-7m (the driving-
clock stopped through the slipping off of a band). From 6h 45*7m till 8h 23*2ra,
which period embraces the time from 16'3m after the beginning, till 15'6m after
the end of totality, a number of galvanometer readings were taken. Since,
however, it became practically impossible to make sure of the lunar image being
concentrated on the thermopiles (owing to the extreme faintness of the eclipsed
moon), these observations, though given further on, could not be utilized for
the construction of the final heat-curve. Observations began again at 8h 28-2m,
and lasted till llh 52-7m, with the following interruptions :—9h 18'2m to 23'2m
(the clock-sector had to be wound back); 9h 26'7m to 27"7m (one reading was
missed); 9h 50-7m to 52*2™ (two readings were missed); 10h 49-2m to llh 19-2m
(observing was stopped for thirty minutes). It will be perceived from the above
that observing was practically carried on from 7h 19m till 15h 45m mean time
Greenwich, during which period I read off the galvanometer altogether 638
times.

486

Boeddicker — On Lunar Radiant Heat.

4. As in 1884, the differences of the consecutive readings of the galvanometer
were taken together in groups of ten, and the mean of each group was assumed to
represent the heat-effect corresponding to the time of the sixth of the eleven
readings which furnish the ten differences. Owing to the observations forming
an all but uninterrupted series, this grouping was proceeded with from difference to
difference, so that the epochs of the heat values vary generally speaking by 0'5m
sidereal time only. Thus each reading was submitted to exactly the same treat-
ment ; and 473 values for the lunar heat were obtained. Of these 446 were
available for the construction of the final heat curve. The first value, namely,
corresponding to 3h 22*7m (or lh 4*2m before the first contact with the penumbra)
was excluded, as the Moon was still very low at that time, and situated, as seen
from the Observatory, over the town of Parsonstown, so that but little reliance can
be placed on it. And further, the values recorded during totality were excluded
(as mentioned above) because the thermopiles were obviously not fully exposed to
the lunar rays.

It may here be remarked that in the preliminary notes of these heat-observa-
tions which I communicated to Nature (No. 953, vol. xxxvii., February 2, 1888),
and to the Astronomische Nachrichten (No. 2828, February 25, 1888) the observa-
tion of 3h 22'7m was not excluded. The values given in the latter journal, being
expressed in per cents, of the now excluded value, have, consequently, all to be
corrected according to the present detailed publication.

5. The following Tables give the eclipse-observations in full. Their arrange-
ment agrees strictly with Table I. in these Transactions for October, 1885, p. 323,
containing the results of 1884. Any necessary explanations will be found on
pp. 501 and 502.

Boeddicker — On Lunar Radiant Heat.

487

TABLE I.

LUNAR HEAT DURING THE TOTAL ECLIPSE OF JANUARY 28, 1888.

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

G..

VI.

log p2.

VII.

logij'2.

VIII.
e.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

G,*.

XI.

Gz*
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m

3 22-7

530-0

± 7-0

68-2

726-3

0-0013

0-0000

0

2-70

h m

- 3 55-8

722-3

4 9-2

535-5

13-1

61-6

652-5

•0010

•27

9-3

648-9

658-0

+ 9-1

19-2

555-9

5-1

60-2

665-1

•16

2 59-3

661-6

655-3

- 5-8

•7

554-6

6-1

•1

663-0

•16

58-8

659-5

655-3

- 4-2

20-2

554-3

6-1

•0

662-1

•15

•3

658-8

654-1

- 4-7

•7

555-3

5-8

•0

662-8

•15

57-8

659-4

653-6

- 5-8

21-2

555-3

5-8

59-9

662-4

•15

•3

659-1

653-1

- 6-0

•7

557-3

6-9

•8

664-2

•14

56-8

660-7

652-7

- 8-0

22-2

558-0

7-0

•7

664-5

•14

•3

661-0

652-2

- 8-8

■7

559-5

6-3

•7

665-9

•13

55-8

662-4

651-8

- 10-6

23-2

557-2

8-1

•6

662-8

•13

•3

659 4

651-2

- 8-2

•7

554-9

8-4

•5

659-4

•12

54-8

656-0

650-7

- 5-3

24-2

554-2

8-2

•5

658-2

•12

•3

654-6

650-0

- 4-6

•7

552-8

9-8

•4

655-7

11

53-8

652-2

649-4

- 2-8

25-2

550 2

11-4

•3

652-4

•11

•3

648-9

648-6

- 0-3

•7

548-5

11-6

•2

649-8

•11

52-8

646-5

648-0

+ 1-5

26-2

545-8

10-3

•2

646-2

•10

■3

642-7

647-2

+ 4-5

•7

541-4

9-0

•1

640-3

•10

51-8

636-9

646-4

4- 9-5

27-2

540-9

8-4

•0

639-3

•09

•3

636-0

645-7

+ 9-7

•7

540-8

8-3

58-9

638-6

•09

50-8

635-3

645-0

+ 9-7

28-2

542-8

8-7

•9

640-4

••

•08

•3

637-2

644-1

+ 6-9

•7

546-1

108

•8

644-0

•08

49-8

640-7

643-2

+ 2-5

29-2

547-1

11-4

•7

644-9

•08

•3

641-6

642-4

+ 0-8

•7

550-1

10-3

•7

648-0

o-ooio

•07

48-8

644-8

641-5

- 3-3

30-2

554-4

8-9

•6

652-5

0-0009

•07

•3

649-2

640-6

- 8-6

•7

556-4

8-1

•5

654-5

•07

47-8

651-0

639-8

- 11-2

31-2

557-3

7-6

•5

655-1

•06

•3

651-6

638-8

- 12-8

•7

549-4

22-6

•4

645-4

•06

46-8

641-9

637-8

- 4-1

32-2

540-1

28-1

•3

634-0

•05

•3

630-6

636-9

+ 6-3

•7

540-7

28-3

•2

634-3

•05

45-8

631-0

635-8

+ 4-8

33-2

540-9

27-6

•2

634-0

•04

•3

630-6

634-6

+ 4-0

488

Boeddicker — On Lunar Radiant Heat.

I.

Sidereal
Time.

II.

III.

P.JS.

IV.

z.

V.

VI.

log p2.

VII.

logfl'2.

VIII.

6.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

XI.

&.*
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m

4 33-7

536-8

± 27*4

58-1

628-8

0-0009

0-0000

2-04

h m

- 2 44-8

625-5

633*4

+ 7*9

Q4.»*>

04 Z

yui O

26*6

*0

625-6

■03

"3

522*3

632*4

+ 10*1

7

Pi*37.Q

oo / o

9ft» A
ZO 0

• a

u

fi9Q-l

vu

to 0

A9<*,'ft
ozo 0

001 0

a. 1- p;
-t- 00

*3Q -0
j4 1 »7

4z a

040 Z

Pi9A- ft
0Z0 0

OZZ 0

1 A'*3

1DO
10 _

1 ft'1

lO 1

0 / 0

U

uu y

632-8
611-2
606-1

•97
"95

40*3
3G'8
.3

ozy 0

603*0

ozo 0
u lo y

AT 9- p;
0 1 z 0

— OO

1 /; .0
~r 0 J

-j- y 0

No observations fiom 4^
37-2">to39-2m. 5 Dif-
ferenccs before and 5
D i fferences after tho
interruption.

7

010 0

1 Q-4

iy 4:

•ft

0,

uuu 0

.OK

UO

00 0

0 j / 0

Al 1 -9
01 1 z

1 1 O.Q

t* 1 0 y

4o z

^ 91 • ^

1 A*9
ID j

•ft

0

DUO J

•94

0

000 0

ouy 0

X Q«9

~r y z

Pi9A>4
0Z0 4

90-7

•7

609'1

•94

34*8

00 0 y

ouo 0

4. 9*4.

-fr Z 4

44 Z

Pi9 p»-Q

ozo y

_ v i

•7
f

608"5

•93

.3

605*3

OO ( u

4. 1*7

T 1 '

.7

OZO 0

o

• A

0

607-4

"93

^•ft
00 0

ou** z

ouo 0

4- 1 'A
-f- 14

A Pi -0
40 Z

010 0

99 -7
— /

0

597-0

•93

0

0 i/O y

And.* i

OU1! 1

4- 10*9

"F 1 U Z

• 7

r

^ n q • i
ouy i

91-9

•4

587-8

•92

oz 0

Ool 0

AA9- A
ouz 0

1 1 ft. O

-j- 1 0 u

^ c .O
4b z

Al 7>1
01/ 1

ZO /

•4

"iQfi.fi
oyu 0

.no

V it

0

oyo 0

AA1 -fl
OU1 U

x 7*4
+ / 4

• 7

^1 ft-Q

oi o y

ZO 0

0

J JO

•92

^1 -ft
01 0

oyo 0

oyy 0

+ 4 0

A 7.0

47 z

Pil Ci'7

o i y /

- 0 1

• 9

Z

Ui/J i

•Ql
ux

0

oyo u

A0ft« 1
OJO 1

9-1

+ Z 1

.7

0Z4 1

91*9
Z4 Z

•9
Z

fin^.7

DUO /

"91

00 0

ouo 0

oyo 4

— 4 1

4o Z

010 4

97*4
Z J 4

>1
1

593"3

"90

0

oyu z

p;oj.'Q
0J4 y

x 4*7
+ 4 /

• 7

1

PiAQ* 7

ouy /

zo 0

•a
u

<ififi.<>
OOO 0

•on

9Q*ft

zy 0

000 4

oyo z

x Q -ft

4y z

piaA'4

OUO 4

99. Q

z z y

•A

00<i 0

0

0 / y 4

P1Q1 «7

oy 1 /

x 1 9* Q

+ iz 0

.7

7

PiA4 >Q

ou4 y

9A-7
ZU /

00 y

yOv 0

•Rfi

9Q -ft
ZO 0

0 / / 0

oyu u

_l 10-7
x lz /

50*2

Pil Q'Q

oio y

97* A
Z / 0

• ft
0

• Qfi

00

0

00/0

000 Z

+ u y

.7

7

f*»99* 1
OZZ 1

9A-9

zu z

f

599'5

•fifi
00

97-Q

oyo 4

PiftA- Q
OOO 0

1 A*l

— 1U 1

0 1 z

ci 7.1
01 / 1

1 ft 'Pi
10 0

*7

ouo ±

•fi7

a

oyu 0

004 O

a -7
— 0 /

.•7

7

Pi 1 Q* A

oiy u

iy 1

•A
0

OJO 0

•87

OR -ft
ZO 0

P109 • 1

oyz 1

P\ft9« 7
OoZ /

Q.4

— y 4

OZ Z

a o a • 7
ozu /

1 ft • Q
10 0

0

OD

O

£Q*2 '7

Oyo /

PlftA-7
OoU /

1 Q ■ A
*— lo U

7

010 Z

1 ft .Q
10 0

• p;
0

0 JO t

OD

Z0 0

oyu 0

0/04

1 O.O
— IZ Z

eo.n
OO Z

0/0 4

1 9 • A
1Z U

4

fi09*Q

00

0

^QQ-ft

oyy 0

A7A- 1
0/01

no .7
— ZO /

• 7

7

P»9A •,!
OZO 4

1Z u

0

602'6

OO

94 -Q
Z4 O

oyy 0

0 / 4 U

0 K' A

— ZO 0

04 Z

oio y

1 ft «Q

10 y

0

0*

O

oyu /

p;7i -7
0 ( 1 i

— iy u

*7

514-1

26'0

■2

587-9

•84

23*8

584-9

569*1

- 15-8

55-2

504*4

20-3

•1

576-2

•83

•3

573-3

566*9

- 6-4

•7

502*4

18*9

•1

573-7

•83

22*8

570-9

564-2

- 6-7

56-2

501*0

18*9

•0

571-9

•83

•3

569-0

561*5

- 7-5

•7

493-1

18-0

54-9

562-6

•82

21*8

559-8

559-0

- 0-8

Boeddicker — On Lunar Radiant Heat.

489

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

Gt.

VI.

log p\

VII.

logjK'*.

VIII.

6. "

IX.

Sid. Time

from
Middle of
Eclipse.

X.

G>*.

XI.

Gz*
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m
i "i7-9

487-2

± 19-5

54-8

555-5

0-0008

0-0000

1 -82

h m

— 2 21-3

552-7

556-2

+ 3-5

480-4

20'7

•8

547-5

"81

20'8

544-8

553-8

+ 9-0

18-9

OO it

478-3

18-7

• 7

544-9

•80

.3

542-1

550-9

+ 8-8

.7
1

476-7

16-8

542-6

•80

19-8

539.9

548-2

+ 8-3

69-2

475.4

19-0

-6

541-1

•79

•3

538-3

545-6

4- 7-^

r to

•7
1

469-8

21-9

•5

534-3

•79

18-8

531-6

542-8

+ 11*2

5 0-2

468-8

22-1

•5

532-8

0-0007

•78

•3

530-2

539.9

4- 9-7

T i* (

.7

467*4

21-3

•4

531-1

•78

17-8

528-4

537-0

+ 8"6

1*2

463-2

20*0

•3

526-1

•78

•3

523-5

534-1

4- 10-6

-7
1

463-3

20-0

•3

525-9

•77

16-8

523-2

531-2

+ 8-0

2-2

466-1

20-0

•2

528-8

•77

•3

526-1

528-3

+ 2-2

•7

469-0

19-1

•1

531-8

••

•76

15-8

529-0

525-7

- 3-3

3-2

465-8

16-2

•0

627-8

•76

•3

525-2

522-7

- 2-5

.7

463'8

15-7

•0

525-3

•75

14-8

522-6

519-9

— 9-7

7-n
10-2
■7

440-l

427- 1

428- 9

27-3
20-9
22-2

53-5
•1
■1

496-9
480-7
482-5

••

•70

■69
•68

11-5
8-3
7-8

494-4

478- 3

479- 9

500-2
478-9
475-4

+ 5-8
+ 0-6
- 4-5

fun oTiQ^rvn ti nna -frnm Mi
liU UUocl V CtblULla J.1UU1 0

6-2"> to 7-7m. 5 Dif-
ferences before and 5
Differences after the
interruption.

11-2

429-1

22-2

•0

482-6

•68

• 3

480-1

471-9

— 8-2

.7
1

431-2

21-7

52-9

484-8

•68

6 '8

482-2

468-1

— 14-1

14 it

22- 7
00.9

389-3
322-0
320'2

39-2
15-7
15-2

•2
51-5
•4

435-2
353-3

356-0

O-OOOfi

•63
•58
•58

1-3
1 55-8
•3

433-0
356-6
354-3

423'5
370-9
366-0

— 9-5
+ 14-3

4-11-7

nu u u Ot I V Jl I'J 1 1 ^ 11 uiil 0

14-2m till 20-2-n. 5

d-J 1 11 L 1 1_ 1 11. ta UClUl C lLI 1 1 1

5 after the interrup-

• 7
1

317-2

16-5

•3

352-6

0 1

54-8

351-0

361-1

+ 10'1

24'2

316-1

15-9

•3

351-2

•57

•3

349-4

356-3

+ 6-9

.7

311-8

16-2

•2

346-2

•56

53-8

344-5

351-1

+ 6"6

25-2

312-0

14-4

• 1

346-3

•56

.3

344-6

346-3

4- 1 -7

•7
1

313-2

13-5

• 1

347-4

•55

52-8

345-7

341-2

— 4-5

26-2

311-4

14-0

•0

345-3

•55

• 3

343-8

336-7

— 7-1

.7
1

306-0

15-9

•0

339-1

•54

51-8

337-5

332'0

— 5'5

27*2

303-5

18-1

50-9

336-2

•53

• 3

334-7

327-1

— 7-fi

•7

294-7

13-8

•8

326-3

•53

50-8

324-8

322-1

- 2-7

28-2

290-4

14-4

•8

321-5

•53

•3

320-1

317-5

- 2-6

•7

289-8

14-5

•7

319-6

1-53

49-8

318-2

312-6

- 5-6

29-2

283-9

11-7

•6

314-1

•3

314-5

308-0

- 6-5

•7

279-1 .

12-0

•6

308-6

48-8

309-0

303-1

- 5-9

TEA.NS. EOT, DUB. SOC, N.S. VOL. IT., PART IX.

490

Boeddicker — On Lunar Radiant Heat.

I.

Sidereal

II.

G.

III.

P. E.

IV.

2.

V

G..

VI.

log p\

VII.

Log72'2.

VIII.

e.

IX.

Sid. Time

from.
Middle of
Eclipse.

X.

XI.

XII.

Curve
minus
Observ.

Remarks.

h m

5 30-2

271 "5

± 10-9

°

50'5

300-0

0-0005

a .a a a a
U UUUU

h m

1 48-3

300-4

298-5

— 1-9

'

263-8

14-2

•4

291-4

47'8

291-7

293-7

+ 2-0

31-2

256-9

14-2

■4

283'6

*'

•3

283-9

289-1

+ 5-2

•7

256-2

14-0

■3

282-7

'*

"

46'8

283-0

284-3

+ 1*3

32-2

254-1

14-4

"2

280'3

"

•3

280-6

279-9

- 0-7

•7

250-4

14-9

"2

276-1

**

45*8

276-4

275-0

— 1-4

33-2

245-7

13-9

-1

270-8

* *

* *

•3

271'1

270-8

— 0-3

•7

239-3

11-9

•0

263-6

44-8

263-9

265-9

+ 2-0

34-2

232-7

11-4

•0

256-3

••

•3

256-5

261-6

+ 5-1

•7

228-0

10-9

49-9

250-9

43-8

251-3

257-0

+ 5-7

35-2

223-3

12-4

•8

245-8

•3

246-0

252-2

+ 6'2

•7

221-8

13-1

"8

244'0

* *

42'8

244-2

247'6

1 O . A

38-5
41-2
•7

205-4
192-9
185-2

9-3
19-1
13-2

•4
-1
-0

225-4
211-3
202-8

* *

"

40-0
39-3
36-8

225-7
211-4
203-0

221*2
196-3
191-8

A . C

— 4 0

— 10 1

— 11-2

No observation, from 5h
38-2m to 38-7m. 5 Dif-
ferences before and 5
after the interruption.

42-2

181-9

14-1

-0

199-0

* *

•3

199-2

187*1

— 12-1

•7

176-6

14-1

48-9

193-2

* 1

* *

35-8

193-4

182-8

— 10-6

43-2

170-8

16-5

-8

186-7

• *

* *

•3

186-9

178-2

— 0-7

•7

166-5

15-3

-8

182-0

* *

34'8

182-2

173'9

— 0 0

44-2

160-2

16-2

•7

175-0

•3

175-2

169-6

— 5-6

•7

149-8

12-1

•7

163-6

33-8

163-8

165-0

+ 1-2

45-2

142-4

14-4

•6

155-4

0-0004

•3

155-6

160-8

+ 5-2

•7

138-2

15-8

•5

150-8

* *

* *

32-8

151-0

156-4

+ 5 4

46-2

132-9

14-4

•5

145-0

* *

•3

145-1

152-2

+ 7 1

54-2
6 2*2
•7

86-8
32-2
35-4

30-5
9-8
10-7

A T . C

47 5
46-5
•5

94-1
34-7
38-2

• *

0*0003

* *

24*3
16-3
15-8

94'2
34-7
38-2

92-2
50-4
48-8

— 2'0
+ lo-7
+ 10-6

No observations from 6h
48-7m till 6h 0-2«. 5
Differences before and
5 after the interrup-
tion.

3-2

37-5

10-6

•4

40-4

• *

* *

•3

40-4

46-2

+ 0 8

•7

36-6

10-3

•3

39-4

• •

14-8

39-5

45-6

4- 6-1

4-2

38-6

10-6

•3

41-6

•3

41-6

44-2

+ 2'6

•7

41-5

11-2

•2

44-7

13-8

44-7

431

- 1-6

5-2

43-7

9-0

•2

47-0

•3

47-1

42-0

- 5-1

•7

42-4

10-5

•1

45-6

12-8

45-6

41-0

- 4-6

62

42-1

10-2

•0

45-3

•3

45-3

39-9

- 5-4

•7

39-5

10-1

•0

42-5

11-8

42-5

38-9

- 3-6

Boeddicker — On Lunar Radiant Heat.

491

I.

Sidereal
Time.

II.
G.

III.

P. E.

IV

z.

V.
<?..

VI.

log p2.

VII.

logiT.

VIII.

€.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

Gz*.

XI.

Gz*

Curve.

XII.

Curve
minus
Observ.

Eemakks.

h ro
fi 7-9

0 | it

OD u

+ 1 n • 1

X 1 u 1

40 &

OQ.O
OO -

a- aaa9

A-AAAA

0

h m
— 1 11 O

QQ>9

oy z

0 < y

1

•7
I

33.4

9*4

y

1U 0

00 y

O ( u

1 i.i

XX

8-9

O it

OU — ■

1 a-a

0

a

0

oO 1

1 o.c
■f" 00

•7
1

97-4.

it t *

0 9

.7

9Q-4.

y 0

zy 4

OO 0

+ 5-9

y it

98-fi

•7

O

oU /

04 0

"i~ 0 y

.7

■to 0

•A
0

97.7

Q*Q

97.7
-1 I

00 y

4- fi-9

IV it

9A-9

iiO it

1U 0

0

9Q> 1
-0 1

O

iiO 1

OO 1

a. fi-n
-r u v

• 7

11 O

•fi

QO-7
oZ i

Oi /

o_ O

— u X

11-2

33-5

12-0

•4

35-9

•3

35-9

31-9

- 4-0

•7

30-8

13-1

•4

33-0

■■

6*8

33-0

31-3

- 17

12-2

32-0

13-0

•3

34-3

•3

34-3

30-9

- 3-4

•7

34-8

12-9

•3

37-3

5-8

37-3

30-4

- 6-9

132
19-2
24'2

.7
4

fi .tQ-S
8 1-7

34-9
24-8
20'2
n-fi

u y
1 -1

+ 6-5

13-4
11-1

g.5

7-A
7.0

7-1
/ X

LOO

•2
44-5
*0

37-4
26-5

91

iiL O

A.A
U D

A.Q

1 >9
— X it

1 c.7

0-0001

a .ArinA
U UUUU

y yyyo

"

•3

0 59-3

?\A-1
04 0

OU O

on . 0
O

1 A 1 Q.O

37-4
26-5

91 -fi

A . C
U O

A . A

0 y
1 .0

j_ A .7

30-0
26-0
it^ y

- 7-4

- 0-5
+ 3-4

C No observations from 6h
15-7m to 22-7. 5 Dif-
< ferences before and 5
I. after the interruption.

ATpan nf ritt TliflFprpnpps:

only.

fih 18.9m till Rh ?A-9m
O lo a till 0 Ou

These values are very
doubtful, since the
moon's heat -was not
fully concentrated on
the thermopiles (see
page 48o).

n.n

it it

11*1
XXX

O .A

7

O. A

•7

4

X X 4

■9

0-0

~ y

44 Z

it y

3*2

xu \J

.1
1

4 0

7

4 0

• 7
i

7-3

0 0

.1
1

< 0

40 /

7. S
< 0

4-2

4"1

.1
1

4 it

7

• 7

0 0

fi-9

.1
1

A ■ Q

A Ca O

4b\J

4 b

S-9

0 u

R'A
0 4

■A
U

O.I

0 J.

"

•7

3*1

7

x X

4.-A

• A
U

* *

47'2

4-2

"

6"2

^•9

A *±
4 4

•a
u

0.0

0 0

•7

3"3

•7

* 4

A.C.
% u

fi-9

0 it

• a

A -R
4 0

48-2

4-6

O X

4 it

O'Ji

•7

3'2

•7

2-7

5-1

•0

2-8

49-2

2-8

8-2

6-2

7-6

35-9

6-4

•7

6-4

•7

10-4

11-9

•9

10-7

50-2

10-7

9-2

8-2

12-9

•9

8-4

•7

8-4

•7

7-2

13-6

•9

7-4

51-2

7-4

3Z2

492

Boeddicker — On Lunar Radiant Heat.

I.

Sidereal
Time.

II.

Cr.

III.

T> TP

IV.

z.

V.

VI.

log p1.

VII.

log it .

VIII.

6.

IX.

Sid. Time

from
Middle oi
Eclipse.

X.

ri it
Crx*.

XI.

Gz*.
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m

8 10-2

8-1

± 13-3

35-9

8-3

9-9995

0-0000

••

h m

+ 0 51-7

8-3

•7

7-9

13-3

•9

8-1

••

• •

62-2

8-1

••

11-2

8-5'

13-3

•8

8-8

••

•7

8-7

•7

5-2

14-0

•8

5-4

••

• •

53-2

6-3

••

12-2

4-1

14-5

•8

4-2

••

..

•7

4-2

••

30-2

7-0

15-7

•4

7-2

9-9993

••

1 11-7

7-2

••

•7

12-8

12-8

•4

13-2

••

12-2

13-1

12-6

- 0-5

31-2

14-4

11-9

■4

14-8

•7

14-8

13-7

- 1-1

•7

17-1

10-0

•4

17-6

••

• • •

13-2

17-6

14-9;

- 2-7

32-2

16-4

1O0

•4

16-9

••

■7

16-8

16-1

- 0-7

■7

16-1

9-3

■3

16-6

••

• •

14-2

.16-5

17-6

+ 1-1

33-2

15-8

9-4

•3

16-3

••

• •

••7

• 16-2

19-1

+ 2-9

•7

17-8

9-4

•3

18-3

••

15-2

18-3

20-8

+ 2-5

34-2

21-5

6-4

•3

22-1

••

• •

•••7

22-1

22-5

4- 0-4

•7

21-2

6-3

•3

21-8

16-2

21-8

24-3

4 2-5

35-2

23-7

7-1

•3

24-4

• •

..-7

24-3

26-1

+ 1-8

•7

23-2

7-2

•3

23-8

••

• •

17-2

23-8

28-0

4 4-2

36-2

29-4

12-8

•3

30-2

.. . .

•■•7

30-2

30-0

- 0-2

•7

37-3

14-9

•3

38-3

18-2

38-3

32-0

- 6-3

37-2

44-0

16-3

•3

45-2

••

• -7

45-2

33-9

- 11-3

•7

43-8

16-4

• -3

45-0

19-2

44-9

36-0

- 8-9

38-2

43-9

16-3

•3

45-1

• ••7'

45-1

38-1

- 7-0

•7

47-6

16-7

•3

48-9

20-2

• 48-8

40-3

- 8-5

39-2

49-8

15-3

• -3

51-2

••

• •

.••7i

61-1

42-6

- 8-5

•7

46-5

19-6

•3

47-8

••

21-2

47-7

44-9

- 2-8

40-2

48-5

19-5

• -3

49-8

••

•7

49-8

47-2

- 2-6

•7

57-7

21-7

•3

59-3

••

22-2

69-2

49-9

- 9-3

41-2

59-8

22-5

•3

61-5

••

—

-••7

61-4

52-2

- 9-2

•7

59-5

22-2

■3

61-2

23-2

611

54-9

- 6-2

42-2

57-6

21-8

•3

59-2

••

• •

•7

69-1

57-1

- 2-0

•7

61-9

21-1

•3

63-6

24-2

63-5

59-9

- 3-6

43-2

67-3

20-7

•3

€9-2

••

■ -7

69-1

62-4

- 6-7

t>y o

• Q
0

714

-■) -

71 o

00 1

— O Z

44-2

70-7

20-8

•3

72-6

•7

72-5

68-0

- 4-5

•7

78-6

10-2

•3

80-8

1 26-2

80-6

70-6

- 10-0

Boeddickek — On Lunar Radiant Heat.

493

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

<?..

VI.

log p2.

VII.

log-K'2.

VIII.

6.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

£,*.

VT

XX.

oz*

Curve.

XII.

Curve
minus
Observ.

Remarks.

h m

Q 4V9

O TV A

7Q-1

± 9'8

35.3

81*3

n-nnnn

h m

-4- 1 26-7

81*2

- 7'8

•7

75. 2

7-fi

4 0

"2

77-3

27-2

77-1
1 < x

t U X

— 1-0

46-2

7n-7
tot

8-1

•2

77-8

•7

77-7
tit

78-9

-4- 1-2

.7

74-8

7-8

•2

76-9

28-2

76-7

81-9

+ 5-2

47-9

79-2

9-4

•2

8T4

.7

81 -3

84-9

+ 3-5

• 7

83-6

9-5

•2

85-9

29-2

85-8

87-9

+ 2-1

48-2

85'6

13-1

.3

88"0

• 7

87'8

90-8

+ 3-0

• 7

85-0

13-0

■3

87-4

30'2

87-2

93'8

+ 6-6

49-2

88-9

1 1 -7

•3

91-4

• 7

91-2

96-8

4- 5-6

.7
i

94-4

129

.3

97-0

31-2

95.9

99-9

+ 3-0

50-2

101-0

12'9

.3

103-8

•7

103-6

102-9

- 0-7

.7

i

110'6

15-8

"3

113-7

32-2

113-4

106-0

4- 2-6

51-2

120-5

22-9

.3

123-8

■7

123-6

109-1

— 14-5

.7

131-4

23-0

.3

135-1

33-2

134-8

112-3

— 22-5

52-2

I37.5

24-4

.3

141-5

•7

141-2

115-3

- 25-9

.7
1

141-8

24'3

•3

145.7

34-2

I45.5

118-4

— 27-1

— 1 x

53-2

I45.5

23-1

•3

149-6

• 7
1

I49.3

121 -8

— 27-5

•7

147-5

21-0

• 3

151-6

35-2

151-4

125-0

— 26-4

64-2

149-2

19.3

•3

153-3

.7

153-1

128-5

— 24*6

.7

155-1

ig -Q

.3

159-4

36'2

159-2

1319

— 27-3

55*2

155-9

19-2

• 3

160'3

.7
1

160-0

I35.4

— 24-6

•7

152-8

19-5

•3

157-0

37-2

156-8

139'0

— 17-8

56-2

148-3

.3

152-4

•7
4

152-2

142-2

— 10-0

.7

146-6

16'0

• 3

150-8

38-2

150-5

145-9

— 4-6

57-2

145.5

15.4

• 3

149-6

•7
1

149-4

149-4

0-0

.7
1

14.7-9

x-± / L

16'5

.3

151-3

SQ-9
0 '.' —

151-1

LOO O

4- 1 -Q

-r 1 y

68-2

151-5

18'4

•3

155.7

.7
1

155-5

156-8

4- 1 -3

X 0

•7

158-8

15-3

*4

163-2

153-0

160'2

— 2'8

59-2

155.9

12-5

•4

170-6

.7
1

170-3

164" 1

.7

165-1

12-2

"4

159-7

1 41 -9

169-4

168-0

1 -4
— x t

9 0-2

171-4

11-7

•4

176-2

9-9992

•7

175-9

171-9

- 4-0

•7

175-0

9-9

•4

179-9

42-2

179-6

175-8

- 3-8

1-2

178-1

7-6

•4

183-1

•7

182-7

179-4

- 3-3

•7

179-8

7-5

•4

184-9

43-2

184-6

183-5

- 1-1

2-2

186-6

10-2

•4

191-9

•7

191-5

187-3

- 4-2

Boeddicker — On Lunar Radiant Heat.

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

V.

<?,.

VI.

log p2.

VII.

log-ffi'2.

VIII.

6.

IX.

Sid. Time

from
Middle of
Eclipse.

X.
Gz*.

XI.

Curve.

XII.

Curve
minus
Observ.

Remarks.

h m
Q 9*7

if it f

1 Q1 • A

i y i d

+ 1 O-Q
X Li, O

3 1-4

60 4

1 Q7 . A

iy / v)

0-0000

y yyyz

O.aaaa

u uuuu

o

h m

1 Q A* A

iyo o

101*0

1 Jl z

— 0 4

o.o
o Z

1 QA*A
i.u<t 4

1 O.I

lo 1

4

1 QQ -O

iyy y

.7
/

iyy o

1 Q Ci*4

iyo 4

A- 1
— 4 1

4

1 Q9-K
iyz 0

1 A -Q

1 4 y

4

1 07. Q

iy / y

40 Ji

1 Q7> K.

iy/ o

1 QQ'9

iyy L

j_ 1*7
+ 1 /

4*2

1 Ql "4.

1 J 1 "i

1 1-A

1 QA-Q

iyo o

•7

1 QA>4

iyo 4

ZUu 0

"t o y

.7
f

1 04 *9
J • ' i it

1 4-4
14 4

• 1
0

1 GO -A

iyy o

40 Z

1 QQ. Q

iyy d

ZU / o

T" O 0

A*9
o z

1 04*3

14-4
14 4

•1

0

1 QQ-Q

iyy o

1

1 OQ« ^

iyy o

91 1 -P.
Zl 1 O

_L 1 9 • 1

■f- 1Z O

•7

194-4

14-9

•5

199-9

47-2

199-5

216-0

+ 16-5

6-2

191-9

17-3

•5

197-3

••

•7

197-0

220-2

+ 23-2

•7

191-0

17-5

•5

195-4

48-2

195-1

224-9

+ 29-8

7-2

190-0

16-7

•5

195-4

•7

195-1

228-9

+ 33-8

•7
f

R*9

O it

•7

Q.O
«7 it

.7
1

i q.4 -4

104 *±

1 Q 1 ■ 1
iol 1

1 01 *Q

iy l o
zuo i

91 1 «1
ill 1 1

1 4-Q
14 O

1 O.A
10 V

00- 1
ZU O

9A- Q
ZD o

Q9 -n
OZ U

• 1

0

• 1
0

■ 1
0

0

-A
D

icy o

1 QA-0

loo X

1 Q7-0

iy / x

ZUO O

- W z

1 o<J
OU
• Q1

4y Z

• 7

ou z

.7

«9
01 Z

1 QQ>0

ioy L
loo y

1 QQ • £

iyo o

91 W* 1

Z1U 1

9 1 Q • Z

Zlo 0

0*3 *?• Q
ZOO O

ZO / o

949-0
Z4Z it

947*0
Z4 / U

911 «Q

zoi y

+ 44 J

1 CI ,Q

+ oi y

i 40.7
T* 4d /

i QA>Q

+ do y

1 QQ. A

+ dd 4

TJVnm Qh 7*7m fill Qh Q-9m

the rays of the moon
were not quite concen-
trated on the piles, so
that the values G from
9h 6-2m till ll-2"> (both
extremes included) are
somewhat too small.

ill z

91 A>9
Z10 Z

dd U

D

0OO-/I

xZZ 4

• Q 1

oi

7

09Q.Q
ZZd O

zoo y

+ 66 1

•7

991-4

zzo 4

Oii i

D

OQ 1 -Q

zdi y

• QO
dX

0Z Z

Zdd Z

9A1 -Q

zoi y

i O Q • 7
T ZO /

11*9
1 1 it

9 4 O-Q

z^u y

dZ X

• A
O

0,4 7.Q
X4/ O

dX

• 7

7

Z4y d

OAA. A

Zoo o

i 17.0

+ 17 o

.7
1

911-4
ZOO 4

QO.A
dZ O

D

O AO -Q
ZDZ o

.90

dZ

Od it

Zo4 6

071 .7
Z/l /

i 1 >A

+ 7 4

19-9
XL it

9A1 -1

Q1 -4
dl 4

• A
0

OAQ-0

zoy u

66

.7

Z/U /

97A« 7
Z/O /

•7

970.-4

94 -9
Z4 Z

• A
D

9Q1 -Q
Zoi O

• QQ
66

04 Z

OQQ -O

Zoo U

ZoZ U

i -n
— 1 U

Lo it

zo4 y

lo 4

• A
D

zyd z

mOA
d4

.7

7

OQ/( .n

zy4 y

OQ n .A

Zo7 4

7. C

— 7 o

•7

290-6

14-5

299-0

•34

65-2

300*8

292*9

- 7*9

14-2

294-3

15-9

302*8

•35

•7

304-7

298*1

- 6-6

•7

297-3

16-2

306-0

•35

56*2

307-9

303*3

- 4-6

15-2

305-5

14-5

314-5

9-9991

•36

'7

316-3

308-8

- 7*5

•7

9IV7

9fi -A
ZO U

97*9

30-2
•7

312-7

Q70- 1
O / Z 0

410 o

41 J. -9

423-7
428-0

12- 8

Old
Q .1

ii y

13- 7
13-4

• Q

O

dO U
1

•2

•2

321-9

00<5 0

428'3
426'8
436-7
441-3

9-9990

•37

• A O

4Z

• A 9

47
•50
■50

57*2

DO

11- 7

12- 2

323-8

dOO'U
431*0

4zy 0

439-6
444-2

314-1

dob y
408*9

A 07 . A

4Z7 U
448-3
451-6

— 9-7

i n . 1

— 22* 1

o.c

— ZD

+ 8-7
+ 7-4

f No observations from 9h
i 18-2™to23-2». 5Dif-
| ferences before and 6
[ after the interruption.
Mean of 7 Differences
only.

No observation at 9h
27,2m. 5 Differences
before and 5 after the
interruption.

31-2

437-3

8-2

•3

450-9

■51

•7

453-9

454-7

+ 0-8

•7

438-8

7*4

•3

452 5

•52

13-2

455-5

457-4

+ 1-9

32-2

437-5

8-5

•3

451-1

•52

•7

454-1

460-2

+ 6-1

Boeddicker — On Lunar Radiant Heat.

495

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

<?,.

VI.

log p2.

VII.

log.?*.

TTTTT

6.

TV

J. A.

Sid. Time

from
Middle of
Eclipse.

A.

<?«*.

YT

Gz*
Curve.

VTT

All.

Curve
minus
Observ.

Remarks.

h m

9 32-7

439.5

+ 8-0

36-3

453.3

0-0000

1-52

h m

+ 2 14'2

456-3

463-4

+ 7-1

33-2

440-0

8-0

.4

453-8

•53

•7

456-8

466-1

+ 9-3

.7

439*1

8-3

•4

452-9

•53

15-2

455-9

469-0

+ 13-1

34-2

439. 0

8-4

•4

452-8

• 54

•7

455-8

471-7

+ 15-9

•7

438-g

S-4

•4

452-8

•55

16-2

456-0

474-3

+ 18-3

35-2

444.3

14-8

•5

458-3

•55

•7

461-6

477-0

+ 15-4

•7

451-1

20-0

■5

465-5

•56

17-2

468-8

479-7

-f 10-9

36-2

455-1

21-3

.5

469-6

•57

•7

473-0

482-0

+ 9-0

7

463-7

24-g

•5

478-6

•57

18-2

482-0

484-3

+ 2-3

37-2

458-1

23-6

•5

483-1

•57

•7

486-5

486-4

— 0-1

•7

469-6

22-5

'6

484-8

•hi

19-2

488-2

488-8

+ 0-6

38-2

472-8

21-5

•6

487-8

•58

•7

491-5

490-9

- 0-6

•7

478-2

19-0

•6

493-7

•58

20-2

497-3

493-0

— 4-3

39*2

483-0

15-7

•6

498-5

•59

•7

502-3

495-0

- 7-3

.7

487-1

12-6

• 7

502-9

•59

21-2

506-6

496-9

— 9-7

40-2

487-0

12-5

•7

502-8

•60

• 7

506-5

498-6

— 7-9

.7

485-6

H-6

• 7

501-3

•60

22-2

505-1

500-3

— 4-8

41-2

485-7

H-7

•7

501-4

•61

•7

505-2

602-0

— 3-2

.7

484-4

10-5

•8

500*2

•62

23-2

504-1

503-7

— 0-4

42-2

488-1

10-2

•8

504-1

•62

• 7
1

507-9

505-1

— 2-8

.7

493-6

9-5

•8

509-8

•62

24-2

513-7

506-8

— 6-9

43-2

497-2

8-0

•9

513-7

•63

• 7

517-6

508-2

— 9-4

•7

499-1

7'3

•9

515-7

•63

25-2

519-6

509-8

- 9-8

44-2

503-4

6-8

•9

520-1

•64

.7

524-1

511-1

— 13 -0

•7

506-9

5-3

■9

524-0

•64

26-2

527-9

512-5

— 15'4

45-2

510-6

7'4

37-0

9-Q9RQ

•65

•7
1

531-6

513-8

— 1 7-R

-I/O

•7

511-0

7-1

•0

528-1

•65

27-2

532-0

514-9

- 17-1

46-2

510-7

7-1

•0

527-8

•66

.7

531-8

516-0

— 15-8

•7

510-0

7-7

•1

527-2

••

•67

28-2

531-3

517-0

- 14-3

47-2

509-0

8-3

•1

526-1

•67

•7

530-2

518-0

- 12-2

•7

506-6

9-1

•1

523-8

•67

29-2

527-8

518-9

- 8-9

48-2

508-3

9-8

•1

525-7

•68

•7

529-7

519-6

- 10-1

51-5

54- 7

55- 2

507-8
507-2
506-9

8-6
10-6
10-7

•3
•5
•6

525-4
525-2
525-2

•72
•75
•75

33-0
36-2
•7

529-5
529-4
529-4

523-9

526- 9

527- 2

- 5-6

- 2-5

- 2-2

No observations from 9h
50-7m to 52-2m. 5 Dif-
ferences before and 5
alter tbe interruption.

496

Boeddicker — On Lunar Radiant Heat.

L

Sidereal
Time.

II.

<7.

III.

P. E.

IV.

2.

V.

VI.

log p1.

VII.

log.K'2.

VIII.

e.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

Gt*.

XI.

Gz*
Curve.

XII.

Curve
minus
Observ.

Remarks.

9 55-7

505-8

± 9-8

37-6

524-0

9-9989

0-0000

1-70

+ 2 37-2

528-2

527-6

- 0-6

56-2

506-3

10-0

•6

524-6

, .

•76

•7

528-8

527-9

- 0-9

•7

504-7

10-1

•7

522-9

•77

38-2

527-1

528-1

+ 1-0

57-2

504-5

9-9

•7

522-6

. i

•77

•7

526-9

528-3

+ 1-4

•7

509-6

10-1

•7

528-1

•77

39-2

532-3

528-7

- 3-6

58-2

508-1

10-4

■8

526-6

•78

■7

531-0

528-9

- 2-1

•7

506-3

9-3

•8

524-8

•78

40-2

529-1

529-1

0-0

59-2

510-4

10-7

•8

528-8

■79

•7

533-2

529-3

- 3-9

•7

513-7

8-9

•9

532-5

•79

41-2

536-9

529-4

- 7-5

10 0-2

515-3

8-4

•9

534-2

9-9988

•80

•7

538-6

529-8

- 8-8

•7

509-3

14-0

•9

528-1

■81

42-2

532-3

529-9

- 2-4

1-2

508-5

13-9

38-0

527-3

•82

•7

531-9

530-0

- 1-9

•7

510-9

13-7

•0

530-1

•82

43-2

534-6

530-0

- 4-6

2-2

512-9

14-4

•0

532-1

•82

•7

536-7

530-0

- 6-7

•7

512-7

14-3

•1

532-0

•83

44-2

536 5

530-1

- 6-4

3-2

514-3

13-4

•1

533-7

•83

•7

538-3

530-1

- 8-2

•7

516-5

14-3

•2

535-9

•84

45-2

540-5

530-2

- 10-3

4-2

516-2

14-1

■2

535-7

•85

•7

540-3

530-2

- 10-1

•7

516-5

14-2

•2

536-0

•85

46-2

540-6

530-3

- 10-3

5-2

517-7

14-3

•3

537-4

•86

•7

542-0

530-3

- 11-7

•7

525-5

6-1

•3

545-6

•87

47-2

550-3

530-3

- 20-0

6-2

527-6

4-8

•3

547-8

•87

•7

552-5

530-3

- 22-2

•7

529-1

4-7

•4

549-5

•87

48-2

554-3

530-3

- 24-0

7-2

529-1

4-7

•4

549-6

•87

•7

554-4

530-4

- 24-0

•7

527-2

5-8

•4

547-8

■88

49-2

552-5

530-4

- 22-1

8-2

525-8

7-7

•5

546-4

•88

. -7

551-1

530-4

- 20-7

•7

523-4

8-2

•5

543-9

•89

50-2

548-6

530-4

- 18-2

9-2

522-4

7-9

•6

542-8

•90

•7

547-5

530-4

- 17-1

•7

525-8

10-2

•6

546 7

•90

51-2

551-4

530-4

- 21-0

10-2

526-5

10-3

•6

547-3

•91

•7

552-1

530-4

- 21-7

•7

526-4

10-2

•7

547-3

••

•92

52-2

552-1

530-4

- 21-7

11-2

525-9

10-2

•7

546-8

•92

•7

551-6

530-4

— 21-2

•7

524-4

10-1

•7

545-3

•92

53-2

550-0

530-5

- 19-5

12-2

524-3

10-0

•8

545-3

•93

•7

550-0

530-5

- 19-5

•7

528-7

11-4

•8

550-0

•93

54-2

554-9

530-5

- 14-4

Boeddicker — On Lunar Radiant Heat.

497

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

<?,*.

VI.

log p2.

VII.

log#2

VIII.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

G-,*.

Ai.

Gx*
Curve.

XII.

Curve
minus
Observ.

Remarks.

b m

10 13*2

531-3

± 9*4

389

552*7

9-9988

0*0000

1*94

h ra
-i- 9 54*7

T it (Jl /

557*6

530*6

— 27'0

.7
1

533-2

8*0

.9

554-9

•95

55.2

560*1

530*6

— 29'5

1 4*9

529*4

12-6

.9

550*9

'95

.7

556*0

530*6

— 25*4

.7
f

521-2

15-8

39. 0

542*5

*95

56*2

547.5

530-7

— 16-8

15-2

516*9

1 7*(1

it V

■0

538*0

9.9937

•97
0 1

.7
t

542*9

530-7

— 12'2

• 7

512-5

1 fi-7

• 1

533*5

■97
f t

57*2

538*4

530-8

- 7'6

16'2

511-6

16-5

-1

-532*7

•17

•7

537*5

530*8

— fi*7

— *j t

.7

511-4

16*4

•2

532-6

•97

58*2

537-4

530-8

— 6*6

if 4

513.3

18*4

•2

535-2

'98

.7

540-1

530 8

— 9*3

.7
f

512*8

1 7*4.
it x

•2

534-3

'98

50*9

539*3

530*9

— 8'4

18*2

511-1

17*1

"3

532-6

•98

.7

537*5

530*9

— 6*6

• 7

509-0

16*8

.3

530-4

'99

^ 0*9

O V it

535-6

530*9

— 4*7

19*2

508-4

1 7*9

it it

•4

529-9

2*00

.7

535-0

530*9

— 4'1

• 7

507*0

19*4

"4

528-5

"01

1 *9

533.5

530*9

— 2*6

20-2

506*1

19-1

•4

527-7
0 it t t

'02

.7

532-7

530*9

— 1'8

.7
1

5(19-1

22-1

"5

523*6

'02

9*9

528-5

531*0

+ 2*5

21-2

493-0

22-4

•5

519*4

'02

.7
1

524*3

531-0

4- fi-7

• 7

495.5

21*9

•6

516*9

•0"?

0 -

521-9

531-0

4- 0*1

22*2

489-5

1 7-5
it 0

•6

510*6

"03

.7
1

515-6

531-0

4- 5-4

T *-* *

•7

483-6

11-9

*6

504*6

•04

4*9
*x 4

509-4

531-0

+ 21*6

23-2

482-1

10-9

.7
<

503-1

'05

.7

508-1

531-0

4- 22*9

•7

479*2

9'3

•7
t

500-2

•05

505-2

531-0

+ 25'8

24-2

480*3

9*6

•8

501*4

'06

•7

506*3

531*0

4- 94*7

*T it^ t

.7

484-5

8*9

-8

505-8

"06

D _

510*7

531*0

+ 20*3

95*9

487-5

10-3

•9

509*1

•07

.7
1

514*1

531-0

+ 16*9

.7

491-2

fi*7

*9

513.3

•07

7-9

51 8*-}

531-0

4- 19*7

~T iit t

9fi*9

492-1

0 **

•9

514-1

•07

.7

c; -I a.o

soi -n
00 ± \j

4- 11*7

Til/

• 7

494-1

1 0

40'0

516-3

•OS

Q-9

0 Z

591 *4

531-0

1 9.5

97-9

it 1 it

496-2

7*1

•0

518-7

•OS

.7
1

59*-**R

531-0

4- 7*9

1 it

• 7
1

498-9

9-0

•1

521-6

•OQ

59fi*7

531-q

4- 4*1}
i- *± 0

28-2

498-3

9-2

•1

521-0

•10

•7

526-2

531-0

+ 4-8

•7

497-8

9-8

•2

520-6

•10

10-2

525-9

531-0

+ 5-1

29-2

497-1

10*1

*2

520-0

•11

•7

525-3

531-0

+ 5-7

•7

494-6

9-0

•2

517-4

•11

11*2

522-6

531-0

+ 8-4

30-2

490-8

11*0

•3

513-5

9*9986

•12

•7

518-7

531-0

+ 12-3

TKANS. EOT. DT7B. SOC, N.S. VOL. IV., PAET IX.

4A

498

Boeddicker — On Lunar Radiant Heat.

z.

Sidereal
Time.

II.

G.

III.

P. i?.

IV.

2.

V.

Gz.

VI.

log p*.

VII.

logi?'2.

VIII.

e.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

XI.

G%*
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m
1U OU /

400 0

i 110

40 0

^1 1 >4.
0114

y yyoo

A. AAA A

0

9* 1 9

h m
~r 0 ILL

OLD 0

^^1 -A

001 \j

_l_ 1 A,A
-\- 14 4

Ql >9
01 Z

400 0

1Z 1

■4
4

^1 1 • **
Oil 0

• 1 9

•7
1

010 0

KOI .A
001 V

J_ 1 4 - P»
+ 14 0

f

40 i 0

1U 0

•4
4

^1 A-l
0 1U 1

1 0

19 «

^ll ^*4
010 4

^^1 «A
001 U

T 10 0

OZ Z

4S9»4.
toL 4

v 0

ouo 1

1 0

.7
f

c -1 n.9

0 1U z

^^1 -A
001 U

J_ 9A«Q
T ZU 0

/

40U 0

O 0

^A9«Q
Ova 1/

•14
14

uOO ^

^ 1 «A
001 U

T" ZZ 0

oo.o

(JO Z

4ftA*9

4:00 _

i ^*a

10 u

•A
O

ouy 0

• 1 ^
10

.7

014 O

KOI .A

JOl O

T 10 0

1

4: JO 4

_o 0

•A
O

^9A-1
OZU 1

•1 ^
10

XO -

001 \J

T 0 0

04 -

4 JO o

99. q

.7
1

• .»-_ 0

• 1 A
10

■j _ 0 1

001 l

4- °.*A
T" u U

.7
f

4Q4*7

9A-9

.7
1

010 1

•1 7
1 i

1 R.O

10 z

^9°.*ft

OaO O

u 0 1 1

T / 0

00 Z

4QA*7

4J 0 /

^0 0

•7
1

^1 4*9
014 _■

•17
1 /

.7
(

0 1 y 0

001 1

~r 1 1 0

•7

490-5

28-7

•8

514-1

•17

17-2

519-5

531-1

+ 11-6

36-2

488*8

29-2

•8

512-5

•18

•7

518-0

531-1

+ 13-1

*7

481-8

31*5

•9

505-3

•18

18-2

510-6

531-1

+ 20-5

37*2

480-4

31-7

•9

504-0

•19

•7

509-3

531-1

+ 21-8

•7

*^S'9

OO £i

.7
1

OJ Z
•7

47A-4.

400 0

44Q>7
44J /

40y y

4°.Q>4.
40y 4

ol 0
ZO t

1 A-4
10 4

1 9»4
1Z 4

1 9»4
1Z ~±

41 *A
41 U

•A
0

. 1
1

1

• 9
Z

4yy y

■±00 /
4 / Z 1

4A1 *Q
401 0

4A1 >4
401 4

• 9A

• 9A

• 91

Zl

• 99

1 Q»9

iy w
•7

9A.9

• 7

91 »9
ZI Z

OVW O

iso y

477- 1
4 / / 1

400 0

400 0

001 1
^°,1 •!

wOi 1

^°,1 *1
001 1

^Ql *1
001 1

001 1

The observations from
10h 37m to 10>> 47m,
being (tlirougli some
unrecognized disturb-
ance) much too loWj
were not utilized for
the construction of the
final curve.

4A>9
4U Z

4°.A»1

14*8
14 0

• 9

Z

400 1

• 99

Lit

• 7

4A°.«A
400 0

ROi .9
001 z

• 7

4°.9*7

40Z t

10 0

0

4 01: 0

• 99

99.9

zz z

4f;q.^
4oy 0

"9

001 4

4 1-9

41 Z

400 4

1 0 J

• 9.
O

400 4

• 9Q
£16

• 7

4AA-4
401/ 4

^°.l *9

001 z

• 7

4°.7«9

40 / Z

10 0

•4.
4

4oy 0

• 9Q
-0

9Q.9

Zo Z

404 0

^^1 *9
001 z

A O • O

4 z Z

AA A -A
44U 4

18-1
10 1

. A

4

4 A9-0
40Z y

VZ4

• 7

7

4A7-Q
40 / y

001 0

, 7

1

40/0

1 fi >A
10 U

0

4AA* Q
40U 0

• 0£

ZO

94 -9

Z4 Z

400 0

001 0

'J o _

4°. 9.
400 0

1 7-Q
1 1 O

• ^
0

4A1 *9
401 Z

• 9(^

zo

• 7
1

4AA«°.
400 0

c;o t .0

00 I 0

.7

7

4/* A>9
44U Z

1/0

0

4AQ. A
400 U

• OA

9 £-9

ZO z

400 Z

001 0

44*2

440 o

7 A. 4

10 4

0

4 AQ «^
400 0

• 9A

*Zo

.7

7

4 74. • A
4/4 U

001 0

• 7

7

A A £«A

440 0

1 A«9

10 I

.7

7

A AQ «0

40o y

• 97

9 A .9

Zo Z

4/40

001 0

40 6

447 7

1 A . A

14 U

7

A 7 1 -9

4/1 _

y yyoo

• 97

• 7

47A> ^
4/00

>A

001 4

•7

449-9

13-6

•8

473-6

•27

27-2

478-9

531-4

46-2

448-0

12-7

•8

471-7

•28

•7

476-9

531-4

•7

447-5

12-4

-9

471-2

•28

28-2

476-5

531-4

47-2

441-9

9-6

•9

465-4

•28

*7

470-7

531-5

11 21-7

485-2

21-3

45-8

520-8

9-9984

•65

4 3-2

528-2

532-3

+ 4-1

Boeddicker — On Lunar Radiant Heat. 499

I.

Sidereal
Time.

II.

G.

III.

P. E.

IV.

z.

V.

VI.

log p-.

VII.

l0giJ'2.

VIII.

€.

IX.

Sid. Time

from
Middle of
Eclipse.

X.

XI.

<?,*
Curve.

XII.

Curve
minus
Observ.

Remarks.

h m

n oo. o

1 X &

487-0
xo / yj

+ 21-3

41-8

•J — a u

y yyox

0*0000

0

2'66

h m
4-4 S -7

T X U i

530-6

532-3

4- 1 -7

•7
1

4Q0-S

TtfV O

20 "1

•Q

•fi7
o 1

4..0
x —

534*8

532-3

— 2-5

4.Q1 - 8

xy X O

I9.9

46*0

,i9fi* ^

O-'i 0

•fi7

O 1

• 7
1

536-2

532-3

— 3-9

•7
1

xyu -

90-4

•n

V

5-2

•i-U-fi

532-3

— 2*3

•

94-9

4X 4

4Q1-fi
xyo 0

1 7-fi

•n

•fi8

.7
1

WOO X

532-3

— 6-1

.7
1

487-9

13-9

.1

1

'J - Li 1

•69

6-2

531-6

532-3

-1- 0-7

25-2

47Q-fi

6*6

■2

1 O 1/

•7n
1 o

.7
1

•19^-fi

532-3

4- 8-7

T Ol

•7

479.9

6'5

•2

516'5

•70

7.0

524-1

532-3

+ 8-2

9fi-9

4.78-fi
x f o o

S-4

0 x

• 1

•J 11 /

•71
i x

.7
1

0 — , 0

\JOii O

+ 10'0

•7

479*6

6'1

•4

si vo

•71

/ X

8-9
0 tt

'j — — 0

5323

+ 9-8

97-9

481 -7

U y

•4
x

•79

•7

OZO J

OQ£i O

4- R-fi

T OO

•7

489-4

7-fi

■fi

•*i9fi*0

•79

q.o
y -

<i97-7

'J'J_ 0

4. 4-fi
T x O

28-2

483-0

7-8

•6

*i9n*fi

•79

.7

OLO 0

•J -J— 0

+ 3-8

.7

i

8*1

•B

f-»9vo

/ o

1 n-9

OOii 0

OO4 O

— n-i

29*2

439.3

8-1

.7
1

.70

.7

000 0

-Jo_ O

— 4'0

.7

i

49^.7

8-1

.7
1

uou 0

•74.

/ x

11-9

XX A

•JO _ O

— 6 "4

490-3

10-3

•8

0

0 yyoo

•71
1 0

.7

Out x

^^9-4

UtJi X

— fi-n

.7

1

492-8

9*8

•8

0

fi^9'^
OoL O

•7fi

19-9

OxU 0

OOi x

7-Q
— t y

11 -9

4QQ-1

1 1-8

x 0 0

y

OOiJ *±

•7fi

.7

^47-4
Ox / x

OoZ x

— O V

•7

501-5

12-9

47-n

x 1 U

*"•■ 4.9*0

•77

10 _

00\J V

OOi x

1 7-fi

oo.o

500-7

13'1

• n

u

o± 1 0

•77

.7
1

oxy 0

1 7-1
— x / X

.7
1

499-2

14-6

. 1

X

•77

14-9

OxO u

119 -4

OOi X

— 1 5 - 6

33-2

502-3

1 "5-7

xu /

•9

•78

.7

■i^i -a
00 x 0

119-4

— 1 Q-4.

— x y x

•7

504-4

15-9

•9

545.9

•78

1 <;'9

0 Jx 4

532-4

— 21-8

34*2

503-5

16-2

• Q
O

0^0 0

•7Q

• 7
t

119-4
Qui x

— 21-1

•7

501 -4

16-1

•1

•an

1 A*9
10 -

^^1 -O

119-4
OOZ x

18-8
- xo 0

35-2

499-5

1 Q-7

•4

X

■Jf 1 O

•an

.7
1

S40 -4

Oxy x

119-4
OoZ x

1 7-0
— X / u

•7

493-7

22-8

•1

535*2

•81
0 X

17-9

0x0 0

119-4
004 x

— xu y

36*2

488*9

20-l

•B

•89

Oil

.7

005 /

OOZ x

1 A*1

— xo 0

•7

481-1

1 Q-9

D

-J — O <J

•89

1 Q.O

Mi 0

OoZ x

9.9

37-2

483-8

19-3

•7

525-0

•82

•7

533-1

532-4

- 0-7

•7

482-6

19-1

•7

523-8

■83

19-2

531-9

532-4

+ 0-5

38-2

479-7

17-4

•8

521-0

•83

•7

528-9

532-5

+ 3-6

•7

474-0

13-9

•8

515-0

•84

20-2

522-9

532-5

+ 9-6

39-2

471-7

13-0

•9

512-6

•85

•7

520-7

532-5

+ 11-8

4 A2

500

Boeddicker — On Lunar Radiant Heat.

T
1.

Sidereal
Time.

TT

XI.

G.

TTT
111.

P. E.

TV

z.

V .

Gt.

VI.

log p2.

VTT
Vll.

log*'*.

T7TTT

V 111.

e.

TY
1A.

Sid. Time

from
Middle of
Eclipse.

Y

JL.

Gt*.

YT

Gz*
Curve.

YTT
All.

Curve
minus
Observ.

Remarks.

h m

11 39-7

474-1

+ 14-3

47-9

515-4

9-9983

0-0000

2'85

h m

+ 4 21*2

523-6

532-5

+ 8-9

40-2

478-4

11-1

48-0

520-4

•86

•7

528-5

532-6

+ 4-1

•7

481-5

7-8

•1

523-8

•87

222

532-2

532-6

+ 0-4

41-2

477-5

7-9

•1

519-9

•87

•7

528-2

532-6

+ 4-4

•7

476-2

80

•2

518-6

•87

23-2

526-9

532-6

+ 5-7

42-2

476-4

8-0

•3

519-0

•88

• 7

527-3

532-6

+ 5-3

•7

476-1

81

•3

518-9

•88

24-2

527-2

532-6

+ 5-4

43-2

474-2

6-9

•4

517-1

•89

•7

525-4

632-6

+ 7-2

•7

472-2

8-6

•4

515-0

•90

25-2

523-4

532-6

+ 9-2

44-2

470-3

9-3

•5

513-3

•90

•7

521-6

532-6

+ 11-0

•7

465-1

7-2

•6

507-7

•91

26-2

515-9

532-6

+ 6-7

45-2

461-9

7-7

•6

504-3

9-9982

•92

•7

512-4

532-6

+ 10-2

•7

461-9

7-7

•7

504-6

•92

27-2

512-6

532-6

+ 10-0

46-2

463-6

8-2

•8

506-7

•92

.7

514-8

532-6

+ 17-8

•7

463-2

8-1

•8

506-4

•93

28-2

514-6

532-7

i 18-1

47-2

465-3

9-8

•9

509-0

•93

■ 7

517-2

532-7

+ 15-5

•7

465-0

9-7

49-0

508-8

•94

29-2

517-0

532-7

+ 15-7

48-2

462-3

10-5

•0

505-9

•95

•7

514-1

532-7

+ 18-6

•7

464-9

10-3

•1

509-0

•95

30-2

517-2

532-7

+ 15-5

49-2

466-2

9-7

1

510-7

•96

•7

519-0

532-7

+ 13-7

•7

469-7

9-8

•2

514-8

•96

31-2

523-2

532-7

+ 9-5

50-2

469-4

10-2

•3

514-7

•97

•7

523-2

532-7

+ 9-5

Boeddicker — On Lunar Radiant Heat.

501

6. Exj^lanation of the preceding Table. — Columns I. and II. After the remarks
sect. 4 (page 486), no more need be said in explanation of these columns. Each
value G is, unless anything to the contrary is mentioned in the last column, the
mean of ten differences of eleven consecutive readings of the galvanometer.

Column III. — The probable errors in this column are based on the deviation of
the single readings from the mean ; they give, therefore, a tolerably clear idea of
the steadiness of the apparatus. As was to be expected, the very considerable
increase in sensitiveness of the thermocouples since 1884 has also increased the
probable error of each heat-value G. Besides this, a very great increase is
naturally to be perceived during the periods of the most rapid change of the
lunar radiation. The mean probable errors, the absolute values as well as when
expressed in per cents, of G, according to the phases of the eclipse stand as
follows : —

Before totality.

Average P.E.

in Divisions of

the Galvanometer in °/0 of G.
Scale.

1. Before the first contact -with the penumbra (18 observations), . . ± 8-11 ± 1-47.

2. During the progress of the penumbra (81 obs.), + 19-11 ± 4-14.

3. During the progress of the shadow (52 obs.), ± 12-75 ± 19-88.

After totality.

4. During the progress of the shadow (76 obs.), ± 14-86 ± 22 64.

5. During the progress of the penumbra (88 obs.), ± 13-60 ± 3-68.

6. After the last contact with the penumbra (132 obs.), .... ± 14*55 ± 2-89.

The increase in the last column during the progress of the shadow is here, of
course, chiefly due to the smallness of the values of G, the atmospheric and other
disturbances (as, for instance, the errors of observation) being the same as during
the other periods. The mean probable error of the whole series of 447 observa-
tions amounts to 14*55 divisions of the galvanometer-scale, or to 8*55 per cent, of
the reading G. It appears doubtful whether the sensitiveness of the apparatus
can be pushed much further if the mode of observing entirely in the open air be
adhered to.

Columns IV. and V. — z is the Moon's true zenith-distance, and Gz the lunar
radiation reduced to zenith by means of Dr. Copeland's table for the extinction of
the lunar heat in our atmosphere, given in the Philosophical Transactions of the
Royal Society for 1873, p. 598.

502

Boeddicker — On Lunar Radiant Heat.

Columns VI. and VII. — The factors log. p2 and log. R'2 reduce the values G to
the same distance of the Moon from the Earth and Sun, to those, namely, which
correspond to 7h 18*5m or the middle of the eclipse.

Column VIII. — e denotes the Moon's apparent elongation from the point
opposite the Sun (— before, -f after full Moon) calculated by the formula

cos (tt — e) = sin D sin 8' + cos D cos 8' cos (A — a),
where A = the Sun's right ascension,

D = the Sun's declination,
a! = the Moon's apparent right ascension,
8' = the Moon's apparent declination.

This formula, where (tt — e) represents approximately the Moon's apparent
illuminated phase, is given by Dr. Copeland in the Paper referred to above,
p. 593.

Column IX — Gives the sidereal times counted from the middle of the eclipse
(— before, + after).

Column X. — The values Gz* were obtained by multiplying those given in
Column V. with the factors in Columns VI. and VII., and further with factors
obtained from Dr. Copeland's phase-table (7. c. p. 605), by assuming simple
proportionality. This correction for phase — the effect of which is but slight —
was applied up to the first and after the last contact with the shadow (up to
5h 28'6m and after 9h 8'4m) as was done in 1884.

Columns XI. and XII. — The Gz* were now plotted down as ordinates with the
times as abscissae, and a curve was carefully drawn and read off. These final
most probable quantities are given in Column XI., and their differences from the
observations in Column XII. As mentioned before (supra, p. 486), the first value
(observed at 3h 22"7m) and those obtained from 6h 48*2m to 8h 30*2m were excluded
in drawing this final curve.

The two branches of the heat-curve are reproduced on Plates LIII. and LIV.

Boeddicker — On Lunar Radiant Heat.

503

II. — Construction of a Curve representing approximately the Change of the Moon's

Liqlit during the Eclipse.

1. A short discussion of the heat-curve just obtained is more conveniently-
deferred till after the means have been supplied to compare it with a curve
representing the variations of the lunar light during the eclipse. The dates for
the computation of this curve were obtained as follows : —

The usual formulae (Appendix to Nautical Almanac for 1836) furnished for
the eclipse : —

Semi-diameter of shadow, ...... 2558*8"

Semi-diameter of penumbra, ...... 4511*8

Depth of penumbra, ....... 1953*0

Diameter of Moon, 1905*8

Semi-diameter of Earth (as seen from the Moon), . . 3490*1

Semi-diameter of Sun (as seen from the Moon), . . 971*7

I now assumed the depth of the penumbra to be equal to 80 x 24*4" = 1952,
and for the diameter of the Moon

78 x 24*4" = 1903 -2",

and divided the penumbra by concentric circles into 80 zones, so that the
difference between the semi-diameters of two successive zones was

Rn _ Rm+i _ 24.^ m = o, l? 2 ... 80 and

R° = 4511*8 = radius of penumbra,

Rso = 2559*8 = assumed radius of shadow.

The Moon was now supposed to move uniformly along a semi-diameter of the
shadow, and the arese successively cut off by the concentric circles computed by
the formula

Anm = {<j>nm - i sin 2<f>nm) p2 + (6-± sin 26nm) Rmi

n = 0, 1, 2 ... 78
m = 0, I, 2 ... 80

where p = 951*6 = the assumed radius of the Moon, and consequently = 24*4.

78

The angles <j> and 6 were obtained from

A„m2 + P2-Rm2 , m p sin 6nm . .

Here is

A„ -tt + 39 p

the distance between the centre of the penumbra and the centre of the Moon.

504

Boeddicker — On Lunar Radiant Heat.

Thus we obviously have A0° = 0, or external contact, and A7S° = 951*62. rr, or
internal contact between moon and penumbra. Equally E1, E2 . . . i?80 will
respectively cut off the areae :—

^o1 (= 0), A1\ A,1 (= 951 -V-tt).

A02 (= 0), A2, A22 A,2 (= 951-6Sr), etc.

A80 (= 0), A80, A2*a . . . vl7880 (= 951-62-7r).

These areae were rigorously computed for m = 0, 10, 20, ... 60, 70, 80, and, of
course, n = 0, 1, 2 . . . 77, 78 for each m, and the intermediate values interpolated.
The portions of the Moon, lying successively in one special zone in, enclosed by
the two concentric circles described with Em~l and Em will then obviously be

A{l-\ A2m~l - Axm, A3m'1 - A2m, etc. till A^-1 - A„m

where now m = 1, 2, 3 . . . 80.

2. I next computed the uneclipsed areas of the Sun (as seen from the Moon) for
80 points of equal distance, thus obtaining 82 values A0*, At*, A2* . . . Aso*, Asl*,
of which A0* = 100 denotes the full, and A8l* = 0 the totally eclipsed Sun as seen
from the Moon during the progress of the eclipse. These quantities, which
represent approximately the luminosity of the successive penumbral zones — if we
neglect the decrease of the Sun's light towards its limb — were plotted down in a
curve, and the numbers corresponding to the middle point of each zone read off.
These values

F0 (= 100), F1} F2,... F80, FS1 (= 0)

are the light-factors, with which the portions of the Moon which lie in the,
corresponding zones of the penumbra have to be multiplied in order to represent
the Moon's luminosity during the progress of the eclipse. At any particular
moment — that, for instance, of internal contact between Moon and penumbra, the
Moon's luminosity will then be expressed by

A1f? F, + (A772 - An*) F2 + (A7i - A-,2) >. + .-..

+ (A"\79.m)-A""\79.m + l)) Fm + . . . + {A? - A]«) F77 + A? F7S.

Thus 159 quantities were deduced which represent, with considerable approxi-
mation, the changes of the Moon's light during the progress of the eclipse, i. e.
during the Moon's motion through the penumbra into the shadow.

Boeddicker — On Lunar Radiant Heat.

505

3. It may be worth while once more to recapitulate the assumptions at
variance with the facts which I made in order to simplify the computation.
It was assumed that

a. the diameter of the Moon was 1903.2", instead of 1905.8";

b. the diameter of the shadow was 2559.8", instead of 2558.8";

c. the Moon moved uniformly along a semi-diameter of the penumbra ;

d. the Sun's light was uniform ;

e. the Moon's light was uniform.

I do not think that these deviations from reality seriously affect the accuracy
of the result as far as our present purpose is concerned.

4. The values of the lunar heat taken from the final curve (Plates LIII. and LIV.)
were next expressed in per cents, of the value of 4h- 9*2m, viz. 658 0, and the two
curves (light and heat) were drawn on the same piece of paper with the time as
abscissae and the light- and heat-values as ordinates. These curves are reproduced
on Plate LV., the quantities on which they are based (to tenths of per cents., and
from 5 to 5 minutes only) follow below in tabular form. For the sake of
comparison I have added on the same plate and in the same Table the observations
made and the light-curve computed in 1884. The time is counted from the
middle of the eclipse in each case. It will be seen that I have added hypothetical
values during totality, which are simply obtained by connecting in the most
probable manner the two observed branches of the heat-curves, and which
obviously can only give a somewhat vague idea of the course the curves would
have taken had observing been possible.

In comparing the curves of 1884 and 1888 the difference of the magnitudes of
the two eclipses must be borne in mind. I add, therefore, here the necessary
data, from which it will be seen that the more recent eclipse lasted 12 minutes
longer than its predecessor.

First contact with penumbra,
,, with shadow,

Oct. 4, 18,84
Sid. T.
19h 41m
20 41

Jan. 28, 1888.

Sid. T.
4h 26-9m

5 28-6

6 29-4

7 18-5

8 7-6

Beginning of totality,

Middle of eclipse,

End of totality,

Last contact with shadow,

21 40

22 26-5

23 13

0 12

9

8-4

with penumbra,

1 12

10 10-0

TBANS. EOT. DTJB. SOC, N.S. VOL. IV., PAET IX.

4B

506

Boeddicker — On Lunar Radiant Heat.

TABLE II.

LUNAR LIGHT AND 11ADIANT HEAT DURING THE TOTAL ECLIPSES OF OCTOBER 4, 1884, AND
JANUARY 28, 1888, EXPRESSED IN PER CENTS. OP FULL MOON RADIATION.

1884, October 4.

Time from
Middle of
Eclipse.

1888, January 28.

1884, October 4.

Time from
Middle of

1888, January 28.

C 's light.

(£ 's heat.

X's heat.

C's light.

£ 's light.

(£ 's heat.

(£ 's heat.

£ 's light.

— 3h 10m

100-0

100-0

0-0

1-0*

+ 0h 25m

0-7*

00

5

100-0

100-0

o-o

1-0*

30

0-6*

0-0

0

99-6

100-0

o-o

1-0*

35

0-5*

o-o

2 55

98-8

100-0

o-o

1-0*

40

0-4*

00

50

97-8

100-0

o-o

1-0*

45

0 4*

00

45

96-4

99-9

o-i

10*

50

0-4*

o-o

40

94-6

99-6

0-3

1-2

55

0-5*

0-1

35

92-5

98-7

1-2

1-5

1 0

0-6*

0-6

30

90-3

97-4

2-9

2-2

5

0-8*

1-8

25

87-3

95-2

5-4

4-0

10

1-4*

3-9

20

83-5

92-1

8-8

6-3

15

3-0

G-8

15

79-2

88-1

13-6

9-3

20

5-9

10-9

10

74-5

83-1

19-4

13-5

25

9-7

16-0

5

69-0

77-1

26-1

18-9

30

14-0

22-1

0

62-5

70-3

33-8

25-6

35

18-8

29-1

1 55

55-1

62-5

42-1

33-4

40

24-2

37-0

50

47-7

54-0

51-0

41-4

45

30-0

45-4

45

40-7

45-4

59-7

50-0

50

36-6

54-0

40

33-6

37-0

67-9

58-3

65

44-1

62-5

35

26-7

29-1

75-1

65-6

2 0

52-4

70-3

30

20-3

22-1

81-8

71-3

5

60-0

77-1

. .

. .

25

14-7

16-0

87-2

75-4

10

66-4

83-1

20

10-1

10-9

91-4

77-9

15

71-1

88-1

8-8

9-3*

15

7-0

6-8

94-7

79-8

20

74-8

92-1

5-4

7-3*

10

5-4

3-9

97-1

81-3

25

77-4

95-2

2-9

5-8

5

4-5

1-8

98-7

82-6

30

79-0

97-4

1-2

4-5

0

4-0

0-6

99-5

83-6

35

79-9

98-7

0-3

3-6

0 55

3-6

0-1

99-9

84-5

40

80-4

99-6

0-1

3-0*

50

3-3*

o-o

100-0

85-1

45

80-6

99-9

o-o

2-7*

45

3-1*

o-o

100-0

85-6

50

80-7

100-0

o-o

2-4*

40

2-9*

0-0

100-0

86-1

55

80-7

100-0

00

2-2*

35

2-7*

o-o

100-0

86-4

3 0

80-7

100-0

0-0

2-1*

30

2-5*

0-0

100-0

86-6

5

80-7

100-0

0-0

1-9*

25

2-4*

00

100-0

86-7

10

80-7

100-0

o-o

1-7*

20

2-2*

0-0

100-0

86-7

15

80-8

100-0

o-o

1-6*

15

2-0*

o-o

100-0

86-8

20

80-8

100-0

o-o

1-4*

10

1-8*

0-0

100-0

86-9

30

80-9

100-0

o-o

1-4*

- 0 5

1-6*

0-0

40

80-9

100-0

o-o

1-3*

0

1-4*

o-o

50

80-9

100-0

o-o

1-2*

+ 0.5

1-2*

o-o

4 0

81-0

100-0

o-o

1-1*

10

1-0*

o-o

10

81-0

100-0

o-o

1-0*

15

0-9*

o-o

20

81-0

100-0

o-o

1-0*

20

0-8*

o-o

30

81-0

100-0

Noth. — The figures marked with an asterisk (*) are hypothetical only.

Boeddickek — On Lunar Radiant Heat.

507

III. — Discussion of the Observations.

1. Decrease of heat before the first contact with the penumbra.

It might be alleged that this decrease is nothing but a result of the mode in
which the final heat-curve has been constructed, and is as such of a purely-
arbitrary character, and not concordant with actual facts. A glance at Plate LIII.
will, however, suffice to show that such can hardly be the case. I also add that I
drew the curve as much as possible without any bias, keeping myself all the time
carefully in ignorance of the different phases of the eclipse. I think it will have
to be admitted that the curve could hardly have been drawn differently. Even
the assumption that the decrease of heat did not begin until 4h 20m or 22m
would not agree with the observations, and could not be made without
necessitating a sudden and inadmissible bend of the curve at about 4h 23m.
And further, if we assign any weight to the first observation of 3h 22 '7m — even
allowing it to be erroneous to a very considerable degree — the lunar heat would
be run up, as it were, to over 670 at 4h 20% and to about 700 at 3h 23m, or
about an hour before the beginning of the eclipse. Thus a still earlier and, I
think, altogether incredible decrease of heat would be brought about. Not that I
consider the beginning of the decline at 4 11 9"2m as indicated by the finally
adopted curve on Plate LV. any more probable. For I find that at that epoch the
vertical distance of the Earth's centre from the nearest common tangent of Moon
and Sun amounted to round 4685 miles. If we subtract from this the mean semi-
diameter of the Earth, it would leave 725 miles as the approximate height of
the Earth's atmosphere. This inadmissible amount shows that our observa-
tions are too much affected by disturbing influences as to admit of an accurate
determination of the height at which the terrestrial atmosphere begins to
absorb the solar heat. But they enable us to draw a lower limit for this height.
It is evident, namely, that at 4h 24m, or about 3 minutes before the first
contact with the penumbra, the decrease of heat has definitely set in. And this
indicates a height of heat-absorbing atmosphere of our Earth of not less than
190 miles. In any case, however, this result — though of considerable interest —
must be received with caution until it has been confirmed by further observations.

2. During the progress of the penumbra the decrease of heat is decidedly
more rapid than that of light. This must be chiefly due to the advance of the
Earth's atmosphere, which would absorb a greater proportion of the heat- than of
the light-rays. At first the heat-curve is not very steep. This was to be expected,
as at first only those portions of the lunar surface are cut off which have the Sun
near the horizon, and must, therefore, be considerably colder than the central
portions. As the shadow advances these central parts of the Moon become rapidly

1 B 2

508

Boeddickek — On Lunar Radiant Heat.

eclipsed. The heat-curve consequently grows steeper, and becomes more parallel
with the light-curve. Finally, the decrease of heat slackens again, and the curve
begins to inflect, as now only the colder areas of the lunar surface reflect towards
the Earth.

3. At 6h 2-7m, or 26'7m. before totality, the heat-curve intersects the light-
curve, or, in other words, the emitted heat begins to preponderate over the
reflected one. The equilibrium between both kinds of heat, therefore, takes place
at 6h 2'7m, when the total amount measured is about 7*3 % of the Full Moon value.
It is of interest to compare these facts with those observed during the former
eclipse. Though we can only approximately tell the point of intersection in 1884
(since direct observations were not obtained) there cannot be much doubt that it
fell at or near 21h ll'7m, or about 28 minutes before totality, when the total
amount of heat was 9*2 % of Full Moon heat. The difference was to be expected,
and is evidently mainly — if not exclusively — due to the greater magnitude of the
more recent eclipse. It is, however, to be remarked here, that the heat observed
in 1884 before totality is almost certainly too small, as observations were
repeatedly interrupted by clouds. Thus it becomes probable, that the intersection
between the two curves in 1884 took place somewhat earlier than assumed above,
though, of course, an estimate which shall come nearer the truth cannot now be
given.

4. In examining the hypothetical heat-curves during totality (see also page 505)
the striking point is this, that during both eclipses the last residuum of heat must
have been very small. The probable minimum falls in 1888 about two minutes
before the end of totality with about 0*4%, and in 1884 about ten minutes before
the end of the total phase with about 1 %. This small residuum would evidently
represent emitted heat only — its amount is so slight that its reality is somewhat
doubtful. It also falls to such an extent below the probable error of the obser-
vations, that it would certainly not have been perceptible to our apparatus in its
present construction had direct observing been practicable. Yet the character of
the curves on Plate LV. seems to give sufficient evidence that the lunar heat was
at no time actually reduced to zero. Referred to the times counted from the
middle of the eclipse, we have in 1884 a lagging of the heat-minimum behind the
light-minimum of about 35 minutes, in 1888 of about 45 minutes — a difference
again due to the different durations of the two eclipses. From these remarks it
would have been expected that the heat-values before the middle of the eclipse
in 1884 should have been larger (instead of smaller) than the corresponding
quantities of 1888, This anomaly may find its explanation in what has been
said in the preceding paragraph about the uncertainty of the observations made in
1884 before the beginning of the total phase.

Boeddickek — On Lunar Radiant Heat.

509

The point of intersection after totality in 1884 fell at 23h 28"5m (or 62 minutes
after the middle of the eclipse) with 1-8 % of heat; in 1888 it fell near 8h 18-5m,
with 0-6 %• The data of 1888 are constructed hypothetical ones; those of 1884
were actually observed.

5. After the point of intersection the heat- curve (of 1888) keeps almost
parallel to the axis of the abscissas for about six minutes ; then it begins to rise
again, at first slowly, then with increasing rapidity, keeping all the time at a
considerably greater distance from the light-curve than before totality. At the
moment of the last contact with the shadow, for instance, this distance amounts to
17 r\ % against 6^ °/ 0&t the first contact. The same rapid rise was observed in
1884. But the curve of 1884 continued practically parallel to the light-curve till
about 15 minutes after the last contact with the shadow, whereas the curve of
1888 assumes a peculiar S-shaped bend with the greatest elongation from the
light-curve shortly after the last contact with the shadow. I am inclined to
consider this bend as the result of some (most probably atmospheric) disturbance,
and to believe the more parallel course in 1884 the more plausible one. This
would mean that the above-mentioned difference between heat and light-curve
ought to be reduced from 17-^% to about 15 °/o against 9-L % at the corresponding
moment in 1884.

I need hardly add that such an atmospheric disturbance need not necessarily
have occurred at the place of observation, but may have taken place in those
regions of our atmosphere which were transversed by the solar rays before they
reached the Moon.

6. About 16 minutes after the last contact with the shadow in 1884, and about
17 minutes after the corresponding contact in 1888 the increase of heat begins to
become gradually less and less, and in 1888 all but ceases about 7 minutes before
the last contact with the penumbra when the total amounts to 80 -6 %• Up to lh 30m
after this last contact this quantity increases only to 81 % of Full Moon heat.
In 1884 the Moon's heat measured 38m after the last contact with the penumbra was
86*8 % of the Full Moon value, so that, generally speaking, a remarkable agreement
between the observations has been established. In detail, however, there exists a
considerable difference. For whereas in 1888 the heat-curve — as indicated before
— remains practically parallel to the light-curve from 7 minutes before the last
contact with the penumbra, it continued to rise slowly but unmistakably in 1884
till about 14 minutes after the end of the eclipse, and only then showed some
approach to parallelism to the light-curve. It would be difficult to say which of
the two courses is the more probable one. A glance at Plate LIV. leads, however,
to the following consideration in favour of the course of 1884. From this plate it
is obvious that at about 8h 10m some (probably atmospheric) disturbance set in,

510

Boeddickek — On Lunar Radiant Heat.

which, gradually increasing, ended (as far as observed) in reducing the lunar heat
to 460 divisions of the galvanometer-scale shortly after 8h 30m. Unfortunately I
then stopped observing for 30 minutes, so that the recovery of the curve (which
certainly must have taken place during this interruption) was not recorded. The
character of the curve depends, therefore, essentially on the observations obtained
after the interruption, and it is not unlikely that all these last observed quantities
are still to some extent affected by the preceding disturbance, and, consequently,
somewhat too small.

7. A satisfactory explanation of the deficiency of lunar heat after the
end of the eclipse, in spite of the rapid fall to almost zero during the first
half of it, I have as yet been unable to find. One fact, however, which
may have some bearing on the question I may here mention, viz. that the
heat-values of 1884 and 1888 corresponding to the last contact with the
shadow and to the last contact with the penumbra seem to be inversely pro-
portional to the times elapsed since the beginning of the two eclipses. We
obtain, namely, under the assumption of such a proportionality for the heat at
these two epochs in 1884, the figures 38*2 % an(^ 83'9 °/Q, while the actually
observed quantities were 41-4 % and 85*2 %• If this proportionality were actually
established — which is at present not the case as far as my observational material
goes — it would seem to indicate that the amount of lunar heat transmitted by our
atmosphere depends in some way on the amount previously absorbed. The facts
would perhaps have to be imagined as follows. The heat immediately reflected
by the Moon passes almost undiminished through the atmosphere, and thus causes
the rapid rise after totality, while the emitted heat is largely absorbed, so much
the more the cooler the atmosphere is. Thus this absorbed quantity of heat
increases steadily with the progress of the eclipse ; it reaches a maximum towards
the end of totality (or, in other words, the total measured becomes a minimum at
this epoch) and begins then steadily to decrease again. The heat measured after
the end of the eclipse falls thus short of the Full Moon value by the amount of
emitted heat which the atmosphere has absorbed, and rises slowly until the
atmosphere is, so to speak, saturated, or the maximum of possible absorption has
taken place, *. e. until the quantity of heat corresponding to Full Moon has been
reached. The total heat measured after an eclipse must thus be inversely
proportional to the duration of an eclipse. If the above reasoning holds good,
the gradually rising heat-curve of 1884 would be the more probable one. It is
well known that the idea of a very considerable absorption of the lunar heat by
our atmosphere was familiar to Sir John Herschel, as seen from the following
remarks {Outlines of Astronomy, 1873, p. 285): — 11 Though the surface of the Full
Moon exposed to us must necessarily be very much heated, . . . yet we feel no
heat from it. . . . No doubt, therefore, its heat (conformably to what is observed

Boeddicker — On Lunar Radiant Heat.

511

of that of bodies heated below the point of luminosity) is much more readily-
absorbed in transversing transparent media than direct solar heat, and is
extinguished in the upper regions of our atmosphere, never reaching the surface
of the Earth at all. Some probability is given to this by the tendency to disappear-
ance of clouds under the Full Moon, [the italics are Sir John's] a meteorological fact
(for as such we think it fully entitled to rank), for which it is necessary to seek a
cause, and for which no other rational explanation seems to offer."

8. Another explanation of our anomaly might be based on the following
paragraph from E. Neison, The Moon (1876), p. 35 : —

" Hitherto no reference has been made to a question of very considerable
influence in the consideration of the questions connected witli the lunar surface,
and that is with regard to purely local atmospheric conditions ; for from a number
of different observations it has been considered that from local action some
vapours may rise from the surface and play an important part in the questions
connected with selenography. Reasoning from the known condition of the
material constituting the terrestrial surface, it seems not unlikely that when
exposed to the greater temperature to which it has been found that the surface of
the Moon is in part exposed, some such local atmospheric conditions may well
arise ; and that a purely local covering to the surface may well occur in the
interior of a deep formation, from the presence of some constituent of the surface,
first expelled by the heat and then reabsorbed on cooling. Of the terrestrial
surface strata, for example, exposed to the condition under which the Moon exists,
few, if any, would be found where this might not be expected to occur in some
degree, and such would be most naturally supposed to occur in the interior of the
deeper lunar formations where the last influence of any aqueous vapour might be
expected to be manifested."

From this remark we should conclude that during the progress of an eclipse a
steady absorption of vapour would take place, by which some heat would be
developed. After the eclipse the atmosphere would emanate again, and during
this process a certain amount of heat would be consumed or bound until the whole
of the atmosphere is set free. By this amount of heat the total measured after
the eclipse should fall short of the Full Moon value. Under these circumstances
the heat-curve of 1888 after the last contact with the penumbra would be the more
probable one. For it should run parallel to the axis of the abscissas until the
lunar vapourous atmosphere is fully developed, and should then rather suddenly
rise up to the Full Moon value.

It may, of course, be possible that both the hypotheses discussed hold good
and are together adequate in bringing about the observed anomaly.

The above theories I only mention tentatively and with considerable diffidence.
Yet any attempt at explaining a so far unexplainable phenomenon may, I think,
be of some use for future investigations.

512

Boeddickeu — On Lunar Radiant Heat.

Conclusion.

In conclusion I enumerate a series of observations which the preceding pages
have shown to be decidedly desirable and in part possible for the same apparatus
— observations which, as far as feasible, I have already begun, and shall lay before
the public when tangible results have been obtained.

a. The debatable decrease of heat before the commencement of the eclipse
requires confirmation or the reverse as the case may be. The best way to obtain
this will consist in observing the near approaches of the Moon to the Earth's
shadow — or in observing and discussing the lunar heat at Full Moon on every
available occasion.

b. Observations during totality are much needed. I now think that with some
precautionary modifications our apparatus may well yield reliable results, and I
shall certainly try to obtain them during the next favourable eclipse.

c. The heat after the last contact with the penumbra requires careful measuring
during eclipses differing as much as possible in magnitude.

d. It is not unlikely that the behaviour and nature of lunar heat may be recog-
nized if eclipse-observations are carried on through glass. As far as I know, such
observations were only made by Professor Langley on one occasion during totality ;
yet detailed and systematically obtained results appear necessary.

e. Finally, the varying radiation of different parts of the lunar surface — which
may have caused many of the irregularities in the results which form the subject
of the present paper — requires systematic observing. But this will necessitate
either a thorough modification of our apparatus, or perhaps the use of radically
different methods of observation.

Trans. R.Bub. S.ToI. IV.

TSO

Lunar Hi
Total Eclipse 18!
I. Before T

SO"
IV

20"

SO"

OttoBaeddiefor. del Birr Castle Observai

Trans I

/

GltoBc

Trans R-I

3 20

2 C ' 2 10 2 20 2 .10 2 4-0

m

ow
fa

J L

2 .rr 3 0 3 10 3 20 3 30 ^

Last Contact
dth Penumbra
£ 12 r

Hate JA'.

21) 210 220 230 2*0 2]SO 3 0 3 *0 3 20

3 4-0 3 SO 4 O 4 It) 4-20

Last Cbntac t
"w:th Penumbra
10* lCTc

OttoBoeddn

I orster ^CcLitn DuMin

IV.ms K Dub S N S \ ,.l l\

Hate UV

Fig. I. Total Lunar Eclipse, 1884 October 4

Fiar.

[ 513 ]

X.

THE SLUGS OF IRELAND. By E. F. SCHAEFF, Ph.D., B.Sc, Keeper of the
Natural History Museum, Dublin. Plates LVI. & LVII.

[Eead Maech 9, 1891.]

The term " Slug," used in the ordinary sense, is applied to snails without an
external shell. Anatomically, the slugs cannot be grouped into one distinct family
apart from the snails. Even of the few genera inhabiting Ireland, Limax,
Agriolimax, and Amalia must be placed in one family with the Helices, to which
they are much more closely related than they are to Avion and Geomalacus, the
two other Irish genera of slugs.

From a systematic point of view a description of these animals, leaving
un mentioned the closely-related snails, may seem rather unscientific, but this work
has been undertaken chiefly with a view of solving some of the difficulties regarding
the distribution of terrestrial animals ; and land snails having been known to be
transported by sea, as has been shown by Darwin [Origin of Species, 6th ed.,
p. 353), are of less importance in this respect than slugs. The sea, which is the
principal means of communication for other animals and plants between mainland
and island, forms an almost impassable barrier for slugs, sea-water being deadly
both to their eggs and themselves ; therefore, if we find the slugs of mainland and
island agreeing in anatomical characters, we may generally conclude that the
island must have had a land connexion with the mainland at some time or other,
and the more closely related the forms are, the more recent must have been this
connexion.

The slugs of Ireland are very closely related, and in most cases are identical
with those on the Continent of Europe. It is not my intention, however, to
enter in this Paper more fully into the cause of the geographical distribution of
slugs, as I propose to deal with the question in a subsequent communication.

Until quite recently, the tongue, or radula, of Mollusca has formed one of the
chief characters in the classification, and the separation of one species from another.
Specific distinction was based almost entirely on external characters and on

TEANS. EOT. DT7B, SOC, N.S. TOT.. IT., PAET X, 4 C

514

Scharff — On the Slugs of Ireland.

the structure of the radula ; and new species have, in consequence, made their
appearance in overwhelming numbers. Simroth (38) changed this unfortunate
state of things by the production of an elaborate treatise on the German slugs, in
which he bases his classification chiefly on the form of the reproductive organs
and the intestine. He showed that the radula is subject to much individual
variation, and that it is, perhaps, the most unsuitable portion of the slug's body
for the purpose of classification. By his anatomical investigations he was enabled
to reduce considerably the number of Euroj^ean species, as given in such a recent
work as that of Westerlund (44). Among a number of species of Limax mentioned
in the latter work, fifteen supposed genuine species proved, on examination of the
internal organs, to be mere varieties of Limax maximus.

Slugs are not alone of importance as regards the geographical distribution of
animals. I hope to be able to show in a separate chapter that their colour has an
important bearing on the subject of colouring in animals generally.

Thompson, in his Natural History of Ireland (43), mentions nine species of
slugs as occurring in this country. In the most recent list of Irish Mollusca
published in 1888, by Taylor and Roebuck (42), this number has been increased
to ten, but one of these, as I shall endeavour to show later on, is only a variety.
I shall now add four species to the list of Irish slugs, one of which, however, has
already been recorded by Eoebuck (35), in the Journal of Conchology. All these
thirteen species, with the exception of one, are also found in Great Britain. This
one species, viz. Geomalacus macidosus, is not only absent from Great Britain,
but also from France and Germany. It appears again in Northern Spain, in the
province of Asturias. In Ireland it has hitherto only been found in the County
Kerry. This part of Ireland has yielded so many peculiar animals and plants
that it deserves very much more attention than it has hitherto received. A
thorough scientific investigation of that interesting county would, no doubt,
reveal a number of forms new to the British fauna and flora.

The thirteen species of Irish slugs belong to five genera, viz. Limax, Agrio-
limax, Amalia, Arion, and Geomalacus. In most of the British text-books, the
three first are united under the genus Limax, but the reasons for separating them
will be found under the headings of the respective genera. Lessona and Pollonera
(21), and others, have placed the very common Irish slug Limax marginatus
(= arborum) in a separate genus, Lehmannia, but I have not thought it advisable
to adopt this subdivision of the remaining species of Limax.

The species of the three first genera can be very readily distinguished from
those of the genus Arion, by the absence of the caudal gland. This gland is
present in Geomalacus, but it is not nearly so conspicuous as in Arion, in which
its triangular opening at the end of the body is well seen.

The colour of the mucus is not of very great importance, but it is rather

Scharff — On the Slugs of Ireland.

515

characteristic in Amalia carinata and Agriolimax agrestis, being always tough and
sticky in the former, and milky in the latter.

The presence of dark lateral bands in most slugs from the very day of their
birth, has induced Simroth (38) to regard them as an ancestral character; and, in
referring to them, he speaks of the ancestral bands (" Stammbinde "). I merely
use the term " lateral bands," although in many cases there appear, besides the
original ones, two inner bands, one on each side of the median lighter stripe.
These inner bands are separated from the lateral bands by a light stripe, and
another similar stripe is on the outer side of the lateral bands. Thus, we
distinguish band and stripes — the former dark, the other light in colour.

Simroth, in his monograph (38), lias placed much weight in the classification of
slugs on the nature of their food. However, my own investigations tend to show
that there are fungus-eating species among the Limaces as well as the Arions, whilst
most species are not particular as to what sort of food they get. Occasionally
they all turn carnivorous, and cannibalism is of frequent occurrence.

The plan adopted in this Paper is to give a general concise synopsis of the
various genera and species. Under the heading of each species are paragraphs
dealing with : 1, External characters ; 2, Anatomy ; 3, Reproduction ; 4, Habitat ;
5, Food ; 6, General Distribution. The anatomical part has been curtailed to a con-
siderable extent, and only the general outlines of the reproductive organs have been
mentioned, which are sufficient in all cases to distinguish one species from another.
More elaborate accounts on the general anatomy will be found in Nunneley's (31)
and Simroth's (38) works. Neither the shell nor the radula are mentioned, as
they do not afford such easy and reliable evidence in the identification of the
species as the reproductive organs.

The only papers ever published on Irish slugs are those of the Rev. B. J.
Clarke (3), and Professor Allman (1). Although the former is exhaustive as far as it
goes, it deals only with what was then believed to come under the head of the
genus Limax. Professor Allman was the first to describe Geomalacus maculosus. The
subsequent publications containing reference to Irish slugs are more of the nature
of lists.

In Forbes and Hanley's History of British Mollusca (9), a few references
are made to Irish slugs ; and Thompson, in his Natural History of Ireland (43),
gives a complete list of the species with which he was acquainted. A Paper
by Taylor and Roebuck, entitled " Authenticated materials towards a Land and
Freshwater Molluscan Fauna of Ireland " (42), contains the most recent list of
slugs, with a good many records of localities from all parts of the country. For
the past few years Messrs. Taylor and Roebuck have had in preparation a
Monograph of the Land and Freshwater Mollusca of the British Fauna, which no
doubt, will contain a good deal of useful information on the distribution and

516

ScHABPF — On the Slugs of Ireland.

variation of slugs. Mr. Roebuck, especially, has for several years made slugs
his principal study, and has worked with great energy in extending our infor-
mation as regards their distribution in all parts of Great Britain and Ireland.
Before writing this Paper I consulted Messrs. Taylor and Roebuck, who in
consideration of my only dealing with the most neglected portion of the British
Islands, kindly promised their support and assistance in my work. The six
volumes of the Journal of Conchology originated by J. W. Taylor contain a large
number of references and records of Irish slugs.

The most important Memoirs on European continental slugs are those of
Simroth (38) and Lessona and Pollonera (21). The former chiefly deals with
the German forms, and the latter with the Italian. As regards the French slugs,
Moquin-Tandon's (26) work is still the most reliable. Although more recent
observers have added a good many new species, and even genera to the French
Fauna, most of them have to be accepted with great caution.

In concluding these preliminary remarks, I must express my sincerest thanks
to Messrs. A. G. More, F. W. Moore, J. R. Redding, G. Barrett-Hamilton, H. B.
Rathborne, G. H. Carpenter, Rev. A. H. Delap, and Miss Warren, for specimens,
and Messrs. Taylor, Hanitsch, Pollonera, and Simroth, for kind advice, or literary
help. The latter was good enough to submit to me part of the proof of his
forthcoming memoir on the slugs of Portugal and the Azores, which will appear
during the course of the present year.

Synopsis of the Irish Genera.

A. — Slugs without caudal gland. Pulmonary opening behind the middle of the
mantle = Limax, Agriolimax, Amalia.

I. — Mantle with concentric wrinkles = Limax, Agriolimax.

a. Lateral bands, or a band of spots present, = Limax.

b. Lateral bands absent = Agriolimax.

II. — Mantle granulated, and with deep horse-shoe shaped groove, = Amalia.

B. — Slugs with caudal gland. Pulmonary opening in front of the middle of
the mantle == Arion, Geomalacus.

I. — Caudal gland placed longitudinally = Arion.
II. — Caudle gland placed transversely = Geomalacus.

Genus I. — Limax. (Linne*, 1758).

Body elongated, keeled towards the tail ; wrinkles longitudinal on body,
concentric on mantle. Longitudinal bands or bands of spots on body and mantle
always present in adult ; no caudal gland. Pulmonary opening behind middle

Scharff — On the Slugs of Ireland.

517

of mantle. Reproductive pore near base of upper tentacles. There is a solid
internal shell, and the intestine has six convolutions.

In this genus the body is elongated and often strongly keeled posteriorly. The
lateral bands are always present in the Irish species, both on the mantle and body;
but they may become obscured by being broken up into spots (L. flavus), or by the
general body colour in the adult becoming black throughout. There is no caudal
gland. The pulmonary opening is always situated behind a line drawn across
the middle of the mantle. The skin externally is wrinkled, but the wrinkles never
are so prominent as they are in the genus Arion ; they are more pronounced,
however, than in Agriolimax and Amalia, where the skin is almost smooth,
especially in the latter.

There are invariably six convolutions of the intestine, sometimes with an
additional ccecum. The genital opening is just behind the tentacles, and there is
a solid internal shell.

There are three anatomically well-defined species of Limax in Ireland : one of
them, viz. Limax marginatum (= arborum, Bouch), differs so much in the structure,
of the reproductive organs, as well as in that of the radula, that a separate genus
was proposed for it by Heynemann. Simroth (38) was the first to suggest that
Limax variegatus (= flavus) should be united to this new genus Lehmannia, as
both possess a ccecum to the intestine. But although they have this much in
common, the reproductive organs in the two species are not so very similar as to
make it desirable to unite them. I think that if any division of the genus Limax
is made, Limax marginatus {= arborum) and L. variegatus {— flavus) should be placed
in separate genera. The presence of a flagellum in the reproductive organs of
Limax marginatus {— arborum) also shows some affinity to the genus Agriolimax.

Synopsis of the Irish Species of Limax.

I. — Mantle with dark spots on light ground, or uniformly dark = L. maximus.
II. — Mantle with light spots on darker ground — L. flavus.
III. — Mantle with two lateral dark bands = L. marginatus.

Limax maximus, L.

Limax maximus. Linne\ Syst. Nat. 1758. Limax antiquorum, F^russac, Hist.
Moll. 1819. Limax maximus. Jeffreys, British Conch. 1862.

(Plate LVI., figs. 1 and 2.)

Colour of body generally a reddish-gray, with dark lateral bands on body, con-
tinued to the posterior third of mantle, the remainder of which is spotted. Tentacles
long; a faint black line runs along outer margin of foot. Intestine without a coecum.

518

Scitarff — On the Slugs of Ireland.

External characters. — I have attempted to use the markings of the mantle as a
method of readily distinguishing the species of Limax, but there is another way,
though perhaps not altogether scientific, by which L. maximus can easily be iden-
tified. If the mantle be touched with a pencil or other sharp instrument, the front
portion curls round completely towards the source of irritation, whilst in the two
other species the same portion of the mantle will be only slightly lifted. Another
character by which L. maximus (except in very dark specimens) can be distin-
guished, is a faint black line, running along the external margin of the foot, which
is quite absent in L. flavus and L. marginatus. Moreover, L. maximus is always
more slender, and its tentacles are almost double the length of those of L. mar-
ginatus, in specimens of the same size. The largest specimen I have met with
about Dublin, measured 110mm. long, and 9mm. broad; but I took one in May,
near Lough Caragh, Co. Kerry, which in spirit still measures 85 mm. by 14 mm. As
a rule, slugs shrink in alcohol to about one-half their length when alive and fully
stretched out ; but in this case I think the specimen can hardly have been more
than 150 mm. long, which is exactly 6 inches. According to Moquin-Tandon (26),
they sometimes grow to the length of 170 mm. in France.

We must not draw too rigid rules as to the limits of the specific characters of
this species, for it is subject to much variation in colour, though in Ireland it is by
no means the most variable of slugs, as it seems to be in Germany, according to
Simroth (38).

All the specimens I have examined, whether they were of various shades of
gray, or of a dark brownish colour, were anatomically identical. Roebuck, in
his British Slug List (35), refers to Limax cinereo-niger (Wolff) as a form which is
found in Ireland, and which is now separated by the best Continental authorities
from L. maximus. He does not mention them, but Simroth (38), one of the best
authorities, certainly examined the form, and found it to agree with L. maximus.
Roebuck states, in the same Paj^er, that there are important differences between
the species in the genital apparatus, but he does not say what they consist in. I,
myself, have not had an opportunity of examining a specimen which could be
referred to this species, although I have had one or two, which were quite dark
above, but leaving the foot white.*

The original lateral bands are always present in quite young specimens. On
the posterior third of the mantle they assume a horse-shoe shape without being
continued anteriorly. Curiously enough, in the adult, the left part of this horse-shoe
becomes almost always broken up into spots, whilst at the right side it generally

* I hare quite recently obtained a specimen at Glengariff agreeing in every respect with the description
given of cinereo-niger. On examination I found no difference anatomically between it and a typical
L. maximus, except in the origin of the retractor muscle of the penis. This confirms the opinion held
above that cinereo-niyer can only be regarded as a variety of maximus.

Scharff — On the Slugs of Ireland.

519

persists. Thus we usually find that the mantle is uniformly spotted in the adult, except
the part between the respiratory orifice and the posterior margin, where we meet
with an elongated black mark, the remnant of the lateral band of the mantle. (This
is well shown in Reeves' (34) figure of L. maximus.) The general body-colour is
usually of a faint reddish-gray, turning into pure gray in spirit, whilst the dark
spots and bands often become blue. The tentacles are of a light reddish-violet
tint. The mucus, on the nature and colour of which rather too much importance
has been placed by previous observers, is whitish, and not nearly so abundant as
in L. flavus, and L. marginatus.

Anatomy (Plate LVIL, fig. 25). — Both Nunneley (31) and Simroth (38) have
given such detailed descriptions of the anatomy, that I need only refer again to
the most salient features.

Of the six convolutions of the intestine, four are imbedded in the liver, and
two hang freely in the body cavity. The hermaphrodite gland (hg.) is elongated
and large, and is connected with the ovisperm-duct (os.) by means of the
hermaphrodite duct (hd.) which takes its course through a portion of the albumin-
iparous gland (ag.). The ovisperm-duct is thick and well convoluted, and
separates further down into a vas-deferens or sperm-duct (sp.) and an oviduct
(ov.). The former opens into the upper end of a very long penis (p.), to which a
strong retractor muscle (rm.) is attached. The lower portion of the penis unites
with that of the oviduct at the genital orifice, so that there is no vestibule. The
receptaculum seminis (rec.) opens into the lower end of the penis near the junction
of the two ducts. Nunneley (31) gives a good figure and description of the repro-
ductive organs, and although he mistook the albuminiparous gland for the testis,
this is a comparatively unimportant matter.

Of course, as in all parts of the body, there are variations in the reproductive
organs, and it is a matter of opinion whether, in conjunction with external
differences in colour, these should be regarded as sufficient to sub-divide the
species. Lessona and Pollonera (28), who have published an elaborate monograph
on the Italian slugs, are evidently of that opinion, and a good deal may be said in
favour of it.

I consider the shell of so little importance as a distinguishing feature that it
will be enough to say that it is much larger than in any of the other species.

Reproduction. — The eggs, as far as my observation goes, are deposited in
August and September, but I think another deposition takes place earlier in the
year. They are very transparent, elastic and slightly yellowish in colour. Their
length is 6 mm., and width 4 mm. About a month after their deposition the
young appear, and from the first show two distinct lateral bands on the body,
reaching to the posterior third of the mantle. The body-colour at this stage is of

520

Scharff — On the Slugs of Ireland.

a delicate reddish-yellow, the portion of the mantle above the shell being paler,
owing to the transparency of the skin.

Its duration of life has generally been fixed at one year. [See Moquin-
Tandon (26) and Simroth (38).] I took large specimens on the west coast in May,
with reproductive organs almost fully developed, and have everywhere taken
numerous half -grown ones in September ; therefore I conclude that eggs are laid
twice in the year. Lehmann (20) seems to be of the same opinion. It is probable
that large specimens owing to the scarcity of food have less chance of surviving
winter than small ones, so that comparatively few will be fully developed in the
following June. In the West, where the climate is milder, large ones find food
more plentifully throughout the winter, and we thus meet with many full-grown
specimens by May.

Habitat. — u L. maximus" Miss Warren wrote to me some time ago from Co.
Mayo, "is a solitary species, which may be exjilained by the fact that it is a great
traveller." This agrees exactly with my own observation. One finds either a
solitary specimen or two not far from one another, but rarely more.

There are frequent references [see Leach (19), Reeve (34), and Simroth (38)]
to this slug having been found in cellars in other countries, but neither my prede-
cessors Clarke (3) or Thompson (43), nor myself, have ever met with it in the house.
I have found L. maximus in my own garden in Dublin, and in the country
everywhere, chiefly in woods, under stones and tree trunks, and near the sea-
shore, almost within high- water mark, but always locally.

Food. — Simroth (38) observes that the spirit in which specimens of L. maximus
have been killed is never coloured green. He found that plants containing
chlorophyll were always refused, whilst fungi were greedily devoured, and form
the staple food of these slugs. When found in the cellar they may also live on
meat or the juicy stalks of vegetables.

My experience almost agrees with that of Simroth in the above. The speci-
mens which I kept in captivity only once gnawed at the green leaf of a Campanula
after having received no other food for a week.

This species, like many others, occasionally exhibits a strong tendency towards
cannibalism. It appeared to me that, especially where one specimen became
rather sickly, the others would seize upon it and devour it.

Quite recently Gain (10) published some very interesting observations on the
food of slugs. He says — 11 L. maximus is a very dainty feeder, preferring fungi to
all other foods, and it seems to be harmless in the garden." Kew (17) writes on
the same subject, " This species feeds freely on bread, and it also ate Russula
emetica, but ripe berries of Solanum dulcamara were refused."

General Distribution. — Great Britain, throughout Continental Europe and

Schaeff — On the Slugs of Ireland.

521

Asia Minor ; also the islands of Sicily, Corsica, Sardinia, Azores, Madeira, and
New Zealand (introduced), and East Coast of North America (introduced).

Limax flavus, L.

Limax flavus. Linn^, Syst. Nat., 1758. Limax variegatus — Draparnaud, Table
Moll, 1801. Limax flavus— Jeffreys' Brit. Conch., 1862.

(Plate LVL, fig. 3.)

Colour of body, lemon or orange-yellow spotted with gray, the spots being
arranged in bands. Tentacles bluish. The intestine has a ccecum, but there is
no flagellum.

Synonymy. — The name 11 variegatus" of Draparnaud (5), adopted by Moquin-
Tandon (26), Simroth (32), and others, is not correct by the law of priority.
Lessona and Pollonera (21) have pointed out that we cannot remain in doubt about
the identity of Limit's species with that of Draparnaud, as the former refers to
Lister's (22) figure, which is unmistakable.

External Characters. — The species is very constant in its external characters.
This slug appears to be of a uniformly lemon-yellow colour; on closer inspection,
however, we find that the yellow is obscured to such an extent by a delicate gray,
especially on the mantle, that it seems as if there were yellow spots on a gray
ground. Towards the sides of the body and mantle the colour becomes more of
an orange. Specimens taken in my own cellar were more vividly coloured ; they
were always of a deep orange-yellow. But the yellow colour in this slug is
entirely due to an abundant mucus, covering the body at all times. When it is
wiped off, the true body-colour is revealed, which is a dull flesh tint. Although
the secretion from the dermal glands of the back is so intensely yellow, the
ordinary mucus of the foot is colourless and very abundant.

The tentacles present a very striking character, being of a delicate blue
colour. They are shorter and thicker than in either of the two other species of
Limax. But the wrinkles are, perhaps, the most characteristic feature in this slug.
They are closely set, and have been likened by Simroth (38) to strings of pearls
(perlschnurartig).

The largest specimen I have seen was 80 mm. long, by 10 mm. broad ; so that
it is considerably smaller than the preceding species, but rather broader for its
size. Altogether, it is more rounded than L. mazimus, and there is only a faint
indication of a keel at the tail end of the body.

Only once have I seen a specimen which exhibited a trace of a band on one
side of the mantle, but never on the body.

TEANS. EOT. DUB. SOC, N.S. VOL. IT., PART X. 4 D

522 Scharff — On the Slugs of Ireland.

Anatomy (Plate LVII., fig. 26). — There are the same six convolutions of
the intestine as in the preceding species, but L. flavns is distinguished from it,
and resembles the next species, in having a blind process or ccecum attached to
the end portion of the intestine. This remarkable feature induced Simroth (38)
to unite L. variegatus (= flavus) and L. arborum (= marginatus) into one sub-genus.
This author informs us that Selenka had discovered the presence of the coecum ;
however, Nunneley (31) described it thirty years before him. The latter men-
tions that this ccecum consists of but little more than delicate cellular tissue,
that it is always collapsed, and that the contents of the intestine do not pass
down it.

The hermaphrodite gland (hg.) is not so elongated as in L. mazimus ) and is
of a light yellow colour, but the shape of the gland naturally varies very much,
and is therefore not of importance in the diagnosis of the species. The ovisperm-
duct (os.) seems rather shorter than in L. mazimus ; and the receptaculum seminis
(rec.) is larger, and opens into the lower portion of the oviduct (ov.)

Reproduction. — The eggs of this species are at once recognized as distinct from
those of L. mazimus. They are provided with a minute sharp point at each end
of the longer diameter. Those I examined were 7 mm. long., and 5 mm. broad;
but, according to Simroth (38), they vary considerably in size, he having found
some measuring 11 mm. long. They are somewhat yellowish in tint, and rather
firmer in consistency than those of L. mazimus. I found them at the end of
November in an old tree trunk near Dublin, and the young slugs emerged a
few days later. These young ones are much darker than the adults. They are
of a somewhat greenish colour, and many of them had a very distinct light
stripe running down the back, the sides being darker; otherwise they resemble
the adults so much that there is no difficulty in recognizing the species at
once.

In the cellars, where this species is common, I have obtained adults up to
November, but in December not a single adult was seen. They must have died
off, young and half -grown specimens being numerous. The fact of there being
half-grown ones in December also proves that a deposition of ova takes place in
the early months of summer.

Habitat. — L. flavus lives chiefly in cellars and kitchens, but it is by no means
scarce in the country. I have often taken it in woods under the bark of old trees,
along with L. mazimus — always a number of them together. In Germany it seems
to be almost exclusively confined to cellars.

Taylor and Roebuck (42) report its occurrence at Waterford, whilst I have
taken it everywhere in the county Dublin ; and Thompson (43) records its
presence in the North. I have also received specimens from Mr. Barrett-Hamilton
from Wexford.

Scharff — On the Slugs of Ireland.

523

Food. — Clarke (3) states that he kept specimens in confinement on bread,
which they eat voraciously. I tried them with campanula leaves, but they would
not touch them. Gain (10) found that they eat the stalks of cabbage and lettuce,
raw and cooked potatoes, turnips and fruits, but that their favourite food is cream.
Of foliage they took only the holly {Ilex aquifolium) at first, but he induced them
later on to take leaves of the bean plant, bryony [Bryonia divisa), Campanula
latifolia, and others. I have once found them j feeding on a large fungus, and as
they never colour spirit green, I have no doubt that Simroth (38) is right in
concluding that their natural food consists in non-chlorophyllaceous substances.

General Distribution. — Great Britain ; throughout continental Europe and Asia
Minor; also the islands of Sicily, Sardinia, Madeira, the Azores, and Balearic
Isles. It occurs also, but has probably been introduced, on the east coast of North
America and Brazil, as well as in Australia and New Zealand.

Limax marginatus, Miiller.

Limax marginatus, Miiller, Hist. Verm., 1774. Limax arborum, Bouchard-
Chantereaux, 1838, Cat. Moll. Terr, et Fluv., Pas-de- Calais. Limax arborum,
Jeffreys, Brit. Conch., 1862.

(Plate LVL, fig. 4.)

Body gelatinous, only slightly keeled towards tail. Colour, generally a
reddish gray ; dark lateral bands on body, continued to the front of mantle.
Tentacles short. A ccecum in intestine, and a flagellum attached to penis.

Synonymy. — Jeffreys (16), in his text-book, seems to take it for granted that
the species described under the above name by Miiller (28) is identical with
Draparnaud's (5) marginatus, although Draparnaud himself did not feel certain,
on account of its different habits. What Draparnaud described was either the
Amalia carinata (Leach) or a closely allied species ; for, whilst Miiller distinctly
mentioned that his species inhabits the beech, Draparnaud's is a ground slug, and
never ascends trees.

External Characters. — I have already mentioned that the lateral lyre-shaped
bands on the mantle are a most typical character. In very dark specimens these
bands may almost disappear ; but I have never seen one in which they could not
be recognized. The bands alone are sufficient to distinguish this slug from
L. maximus and L. flavus. Moreover, it is distinguished from all other slugs by its
gelatinous appearance, and the slightest touch will cause it to give off a most
abundant watery mucus. It never grows to the size of L. maximus, with which,
by the uninitiated, it might be confounded. The largest specimen I have seen
measured 80 mm.

4 D 2

524

Scharff — On the Slugs of Ireland.

The general body-colour is a reddish or sometimes a bluish gray, which may
be more or less obscured by darker bands or spots. In almost all cases a lighter
stripe is left, which runs along the middle of the back. The posterior third of the
body is carinated, but the keel is not nearly so marked as in L. maximus. The
ground-colour of the mantle is as a rule lighter than that of the body. The
middle portion is gray, and bordered on each side by a strip of light ground
colour. The dark lateral bands almost surround the whole, although they do not
quite meet in front or behind. The head is reddish gray, but it is also subject to
slight variation in colour. The tentacles, as has been remarked before, are about
half as long as those of an equal-sized specimen of L. maximus (fig. 2), and are
somewhat similar in tint.

Anatomy (Plate LVIL, fig. 27). — The interior of the body-cavity, especially
posteriorly, is darkly pigmented. The intestinal convolutions are similar in
number and shape to those of the preceding species, and there is also a ccecum.
The hermaphrodite gland {hg.) is smaller than in the two other species of Limax,
generally dark in colour, and often divided into two portions. The ovisperm-
duct (os.) is thick and short. The sperm-duct (sp.) and penis (p.) very short, the
latter being distinguished by the presence of a flagellum (Jl.) which may be
looked upon as an accessory gland. The receptaculum seminis (rec.) opens, as
in L. maximus, into the lower portion of the penis.

Reproduction. — I kept a number of specimens of this species in captivity from
September until December. Eggs were deposited from the end of September till
the middle of October, on an average about twenty in a cluster. The sizes varied
somewhat, but they were mostly 5^ mm. long by 4 mm. broad, and were
extremely like those of L. maximus — very transparent and elastic. The young
made their appearance exactly four weeks after the deposition of the eggs, and
were of a reddish-violet colour throughout. Even at this stage, from the very
first day of their birth, they are easily distinguished from L. maximus. The
tentacles are about 2 mm. long in the latter, while in L. marginatus they are only
1 mm. in length. The young L. marginatus is born with the lateral bands fully
developed, reaching right to the front, whilst in L. maximus, as we have seen, they
stop short at the posterior third of the mantle. The bands on the body of the
young, as Simroth (38) has pointed out, are not equivalent to those in L. maximus.
In fact, they are not the real lateral bands (Stammbinde), but the inner bands,
which appear much later in L. maximus. As I found a large number of specimens
in September, measuring from 30 to 40 mm., we may conclude that in this species
also there must be a deposition of ova at least twice in the year. Simroth (32)
believes that this species lives through several years, but I venture to think that
more evidence is needed to support this opinion.

Habitat. — Limax marginatus has a wide range in this country. Both

Scharff — On the Slugs of Ireland.

525

Thompson (43) and Clarke (3) found it common in the North, on the stems of
trees after rain. Taylor and Roebuck (42) report its occurrence from Kerry,
Waterford, and other counties. Forbes and Hanley (9) state that they found it
plentifully on bare rocks at an elevation of above 1500 feet near Connor Cliffs,
above Dingle, in Kerry. It is a very common form around Dublin, but it is
peculiar to the open country, and not found in gardens. It is seen both on the
trunks of trees and among rocks, and under stones. The Rev. A. H. Delap sent
me specimens from the Skelligs Rock agreeing in every respect with the main-
land forms. This is a large bare rock, about ten miles from the coast of
Kerry. Neither bush nor tree grows on it, and in westerly winds it is enveloped
in a mist of spray, the waves beating over the greater part of it. From the
Aran Islands in Galway Bay, which are quite bare and rocky, I have also
received specimens, and, no doubt, this species occurs on all the islands along
the west coast.

Food. — According to Lehmann (20) this slug is both carnivorous and herbi-
vorous, but Simroth's (38) experience goes to show that it only touches animal
food when driven by stress of hunger. He also states that the spirit is
coloured green, not by the chlorophyll of leaves, but by that contained in
lichens, and that the latter constitute the real food of L. marginatum.

This is very much my own experience. My captive specimens refused to touch
green leaves or fish, and after four weeks they died from starvation. Although
these observations are of some importance in establishing the nature of food which
slugs live on, further experiments are needed to decide beyond doubt what the
natural food of L. marginatus consists in. Gain (10) states that the specimens
which he kept in captivity would not touch mosses, lichens, or fungi. This may
be due to an unsuitable kind of lichen having been chosen, or else that the slugs
were, for some reason or other, unwilling to feed at all.

General Distribution. — Great Britain, and the greater part of continental
Europe ; also the islands of Iceland and Sicily.

Genus II. — Agriolimax. (Malm, 1868.)

Animal keeled only posteriorly. Mantle concentrically striated, the centre of
striae being somewhat to the right of median line. There are no bands, and if
spots are present they are irregularly scattered over the body. Pulmonary opening
behind middle of mantle, and genital pore near tentacles. The intestine has
four convolutions, and there is a solid internal shell ; no caudal gland.

This genus includes some species which used to form part of the genus Zimax,
and in most modern text-books they are still retained under that denomination.
Of course it is much better not to give up an old well-known name too readily ;
but a large number of species have been found in recent years in various parts of

526

Scharff — On the Slugs of Ireland.

Europe which may, with our two species, A. agrestis and A. laevis, be united into one
group, differing in many important features from the genus Limax. The name
Agriolimax has been adopted by such authorities as Simroth (38), Lessona and
Pollonera (21), and Malm (25), although it is not by all of them used in the same
sense. I have adopted Simroth's definition of the genus. The differences in the
intestine alone are sufficient to separate the two forms A. agrestis and A. laevis from
the Limaces, but there are additional and not less important differences. Agrio-
limax has only four convolutions of the intestine instead of six, and these four are
altogether different in position from those in Limax. In the last genus the left
lobe of the liver formed the apex of the intestinal sack ; in Agriolimax it is the
right. The reproductive organs do not show any very important difference in the
two genera, with the exception, perhaps, of the retractor muscle of the penis. The
chief objection to the more general recognition of this genus among Malacologists
seems to be in the difficulty of fixing a constant character by which Agriolimax
may be distinguished from Limax externally. Simroth (38), however, has shown,
in his excellent monograph, that the species of Agriolimax never at any period of
their lives possess bands. If in some varieties the irregular concentrations of dark
pigment here and there appear to produce a kind of lateral band, we must not be
led astray by appearances. In the genus Limax, on the other hand, lateral bands
are always present, at any rate during youth. They may in later stages unite or
break up into irregular spots, but in almost all cases their presence can be easily
demonstrated.

The food in Agriolimax is different from that of the Limaces. As we have seen
the natural diet of the latter is probably fungi and lichens, but Agriolimax lives
on the higher phanerogamic plants. It is a most destructive pest in the field
and garden, whilst the Limaces are comparatively harmless; indeed, they might
even be called useful slugs.

Synopsis of the Ieish Species of Agriolimax.

I. — Mantle about one-third the length of body. Mucus milky = A. agrestis.
II. — Mantle about one-half the length of body. Mucus colourless = A. laevis.

Agriolimax agrestis, L.

Limax agrestis. Linne\ Syst. Nat. 1758. Limax agrestis, Jeffreys, Brit.
Conch. 1862. Agriolimax agrestis, Malm, Limacina Scandin. 1868.

(Plate LVL, figs. 5 and 6).

Body-colour generally of a yellowish-white, irregularly spotted with gray,
sometimes of a uniform gray or brown ; mantle about one-third the length of body.
Slime milky. A coecum in intestine.

Schaeff — On the Slugs of Ireland.

527

External Characters. — As a rule Agriolimax agrestis may be distinguished from A.
laevis by the colour alone. The former is almost always of a dirty yellowish-white
colour (fig. 5), either with or without diffuse patches of a darker pigment. The
latter may altogether obscure the original body-colour, and produce a bluish slate-
coloured slug (fig. 6). I have had two specimens from the Aran Islands, county
Gal way, which resembled A. laevis in so far as they were of a dark chocolate colour,
but the milky slime, the short mantle, and the more pronounced keel were sufficient
to pronounce them as mere varieties of A. agrestis. Anatomically they differed in
no way from the usual form.

A. agrestis grows to a much greater size than A. laevis, the largest specimen
measuring 40 mm. by 5 mm. According to Moquin-Tandon (26) it reaches the
length of 60 mm. in France.

In a fully extended specimen the mantle occupies exactly a third of the total
length of the body, which is somewhat compressed posteriorly, and there is a well-
marked keel reaching from the posterior third to the end of the body. The head
and tentacles are faintly violet-coloured, but vary according to the general body
tint.

Quite fifty per cent, of the varieties I picked up during the summer in the
country near Dublin were of a uniform yellowish-white, the space between the
wrinkles being marked by a very light gray, so that the shape of each body-
wrinkle was well seen. Once I obtained a perfectly white albino specimen under
a heap of hay at Raheny. In November 60 per cent, of the A. agrestis in my
garden were of a yellowish-white colour, faintly speckled with gray. On the other
hand, of those obtained at the same time from the Aran Islands, 80 per cent, had
the ground colour reddish-yellow, but they were uniformly mottled with dark gray,
two specimens being almost black. The mucus in this slug is very abundant, and
of a milky colour.

Anatomy. (Plate LVII., fig. 28). — There are only four convolutions in the
intestine of this species and the next, as has been shown by Nunneley (31), and more
recently by Simroth (38). But Nunneley did not notice the small ccecum near the
terminal convolution of the intestine. Simroth pointed out that it is not homologous
with that in Limax, being differently situated. The hermaphrodite gland (hg.) is
elongated, and generally the acini composing it are split up like a bunch of grapes.
The hermaphrodite duct (hd.) is almost always straight, i. e. not convoluted like
that in Limax. Close to the genital pore, the ovisperm-duct (os.) divides into
oviduct (ov.) and sperm-duct (sp.). The latter is short and opens into the very large
penis (p.). The receptaculum seminis (rec.) is placed at the junction of the penis
and oviduct. Near the opening of the sperm-duct into the penis, an accessory gland,
the flagellum [fl.), opens into it also, and I found this to vary somewhat in the
different specimens I examined.

528

Scharff — On the Slugs of Ireland.

A Paper dealing with the anatomy and histology of the alimentary canal and
the nervous system has recently been published by Dr. Hanitsch (12).

Reproduction. — The eggs are globular and perfectly transparent, measuring
2 mm. in diameter. The specimens I kept in captivity produced only about
30 eggs each, but according to some authorities the same slug may deposit a large
number during a short period. Thus, Moquin-Tandon (26) mentions that one
specimen has, at different times, produced as many as 300 or even 350 eggs;
and, according to the same authority, Leach is stated to have observed two slugs
deposit 776 eggs. Although, no doubt, this slug is extremely prolific, I ven-
ture to think that further experiments are needed to confirm these observations.
The young do not seem to me to present any appreciable differences from the
adults.

I have taken specimens with fully developed reproductive organs from March
to December. In the latter month and January the large specimens seem to die
off, but it is difficult to determine their length of life. Simroth (38) believes that
they live only one year.

Habitat. — Agriolimax agrestis is to be met with everywhere. It is the com-
monest, and probably the most destructive of all slugs. The damage done by it
in the garden as well as in the field is enormous. It begins its ravages in the
evening soon after sunset, and feeds the whole night through until the morning,
when it retires for the day into worm-burrows or underneath stones and clods of
earth. It seems to be little affected by weather or climate, being equally com-
mon on the islands of the west coast, on the mainland, and on the continent of
Europe.

This slug is very active, and when touched, it glides through the fingers,
leaving a mass of milky slime behind, and rapidly crawls away. As I have men-
tioned, I have seen the very dark variety only from the Aran Islands. The dark
slate-coloured variety, described by Clarke (3), only once occurred to me along
the high road to Whitechurch, near Dublin, and there were plenty of them on
the spot.

Food. — Agriolimax agrestis is very voracious and omnivorous, but I think
green food is preferred. In captivity they seemed to relish anything they were
offered, and in this respect they are very different from most other slugs. In the
garden I found them chiefly injurious to peas. They will eat the young shoots
and the flowers, and even devour the pods. I doubt whether they do much damage
underground to bulbs, which are chiefly preyed upon by Amalia carinata.

General Distribution. — Great Britain, and throughout continental Europe, Asia
Minor, Persia, Siberia ( ? ), Japan, Iceland, Greenland, the Azores, Madeira,
Marocco. It has probably been introduced on the east coast of N. America, in
Brazil, South Africa, and New Zealand.

Scharff — On the Slugs of Ireland.

529

Agriolimax laevis, Miiller.

Limax laevis. Miiller, Hist. Verm., 1774. Limax brunneus. Draparnaud,
Table Moll., 1801. Agriolimax laevis. Lessona and Pollonera, Monogr. Limac.
Hal. 1882.

(Plate LVI.} fig. 7.)

Body of a purplish brown colour. Mantle about one-half the length of body.
Slime watery. Intestine without a ccecum.

External Characters. — This slug has not been recorded before from Ireland. It
was discovered by Mr. Rathborne in Lord Massy's estate at Killakee, near Dublin,
and brought to me for identification. I shortly after found two additional speci-
mens in the same place, i.e. along the banks of an old fish pond. Unfortunately
none of the specimens were full grown, but I at once distinguished it, as I had
expected to find it before, it having a very wide distribution, ranging all over
Europe and America.

The best description which I have seen of this slug is that by Heynemann
(14). According to him A. laevis differs chiefly from the closely allied A. agrestis
by the size of the mantle, which is almost one-half the total length. The back is
only very slightly keeled towards the end of the body, which is of a dark purplish
brown colour throughout. Simroth states that younger specimens are of a dark
gray, but those I found which only measured 3 mm. and 10 mm. respectively
were precisely the same in colour as the largest which measured 15 mm. Its
maximum length, according to Heynemann, never exceeds 20 mm. (about three-
quarters of an inch), so that it is the smallest of our native slugs. The neck can
be stretched out very considerably. The mucus is perfectly clear and transparent,
by which the species can perhaps most easily be recognized.

The shell, especially in younger specimens, is often visible through the mantle,
and its outlines are indicated by a golden yellowish colour.

Anatomy (Plate LVIL, fig. 29). — All the specimens I found being immature, the
reproductive organs were not fully developed. The intestine is similar to that in
the last species, but the ccecum is entirely wanting. The largest specimen,
measuring 15 mm., which I dissected, had only the female reproductive organs
developed. This agrees with Simroth's (38) observations, who found that the
female portion of the generative organs was generally developed before the male
portion. The hermaphrodite gland (hg.) is dark, the rest of the reproductive
organ being much the same as in A. agrestis, with the exception perhaps of the
penis, which, according to Simroth is hammer-shaped, the flagellum being of a very
different shape from that in A. agrestis (32 Plate ix., fig. 17).

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART X. 4 E

530

Sciiarff — On the Slugs of Ireland.

Reproduction. — I have not observed the eggs of this slug. Simroth (38) tells us
that they are about the same size as those of A. agrestis, measuring between 1^5
mm. and 2 mm. in diameter. Moquin-Tandon (26) states that in Limax brunneus
Drap ( = A. laevis) the eggs are l|mm. long and 1 mm. broad, and that the number
at each deposition varies from twelve to eighteen. Simroth found young at all
seasons, but does not give an opinion as to the limits of age in this species, and my
own observations are so limited that I cannot venture to express an opinion.

Habitat and Food. — In Ireland this species seems to be very local, and it cer-
tainly never occurred to me in company with A. agrestis. In Germany it is found
along with A. agrestis in the garden and field, but everywhere it appears to prefer
damp situations, being commonest near banks of rivers or in ditches.

Mr. Burbidge, of the Trinity College Botanic Gardens in Dublin, mentioned
to me quite recently that a little black slug had appeared in his orchid houses. I
managed to secure a specimen, and found it to be an Agriolimax laevis, and I
ascertained that the sphagnum moss so extensively used in the cultivation of
orchids was brought down to Dublin from the neighbourhood of Killakee, the
only locality where I have met with this species.* It seems to thrive in the warm
orchid house, and manages to do a good deal of damage to the delicate flowers.
I have not been able to ascertain what food it lives on in its original home.

General Distribution. — Great Britain, and throughout continental Europe ;
Siberia, and throughout North America and Brazil.

Genus III. — Amalia (Moquin-Tandon, 1855.)

Animal generally sharply keeled along the whole of body behind mantle.
Mantle, which is shagreened or granulated, has a horse-shoe shaped groove. Body
without bands. Pulmonary opening behind middle of mantle. Genital opening near
base of tentacles. Intestine has four convolutions, and there are accessory glands
in connexion with oviduct or vestibule. There is a solid internal shell, but no
caudal gland.

This genus, like that of Agriolimax, has formerly been united with the genus
Limax, and the various species of Amalia are found under the latter genus in such
text books as Jeffreys (16) and Forbes and Hanley (9). In recent years the
structure of slugs and their habits having become better understood, mostly owing
to the labours of Simroth and of Lessona and Pollonera, the grouping under one
genus of a number of miscellaneous forms has been discontinued.

Externally the Irish species are characterized by a sharp ridge or keel
running along the whole of the back. In some of the Continental forms this keel
does not seem to form such a prominent feature. A character which is applicable

* Since writing the above, I found this slug also in Connemara, county Galway, and at Killarney,
county Kerry.

Scharff — On the Slugs of Ireland.

531

to all the species and by which the genus is most readily distinguished from others,
is the deep horse-shoe shaped groove on the mantle. The mantle, moreover, is
different from that in the two preceding genera in being granulated.

As regards the internal organization, the genus is more closely allied to Agrio-
limax than to Limax, but still there are many very important differences. There
are four convolutions to the intestine in both genera, but Amalia has accessory
glands in connexion with the vestibule or oviduct, which are absent in Agriolimax.
On the other hand, the penis in Amalia has no accessory gland or flagellum. The
sperm is transmitted by means of a spermatophore in Amalia, and by a soft
mucous capsule (Schleimpatrone) in the other. Agriolimax is quick in its move-
ments, has a delicate skin and abundant liquid mucus, whilst Amalia is slow, with
thicker skin and often with tough viscid mucus.

Synopsis of the Irish Species of Amalia.

I. — Colour generally brown, foot yellowish, and mucus viscid = A. carinata.
II. — Colour generally black, foot white, and mucus watery = A. gagates.

Amalia carinata, Leach.

Limax carinatus. Leach, Synops. Moll. Brit., 1820. Limax marginatus. Jeffreys,

Brit. Conch., 1862 (not Muller.)

(Plate LVL, fig. 8.)

Colour of body generally brown. Groove on mantle almost always filled with
dark pigment. Skin thick, and interstices between wrinkles filled with black
pigment, and slime viscid. Keel of a lighter colour than rest of body. Foot
yellowish. Receptaculum seminis very large and elongated.

Synonymy. — The name Limax marginatus applied to this slug by Jeffreys (16)
has already been disposed of, having evidently been intended by Muller (28) for
quite a different species. The name L. marginatus has been kept up by Taylor and
Roebuck (42) in their Irish list, and in the Conclwlogical Journal (41), but it has
been discontinued for the British form by Continental authors, such as Simroth
(38) and Lessona and Pollonera (21). I think there is no doubt that the Irish
form is the one described by Leach (19) as Limax carinatus. I was not sure
whether it was the same as the Continental, at least the German form, so I
submitted specimens of several varieties to Dr. Simroth, who pronounced them to be
Amalia carinata, Risso. He tells me they differ but little from the German speci-
mens, hardly sufficiently to attach to them a distinct varietal name. The proofs of
Leach's work (19) were in circulation in 1820, so that his name should be attached
in preference to that of Risso.

4 E 2

532

Sciiarff — On the Slags of Ireland.

External Characters. — A. carinata is at once distinguished from all the pre-
ceding' species by the prominent ridge or keel running from the posterior
margin of the mantle to the end of the body. A less conspicuous feature, by
which this and the next species may be distinguished from all others, is the
horse-shoe shaped groove on the mantle. In A. carinata this groove is almost
always filled with a black pigment, so as to render it more readily visible than
in the next species. Some authors have thought it advisable to create a separate
name for specimens in which the black marking meets in front to form a complete
horse-shoe. However, I have examined a large number of specimens from gardens
in Dublin where it is, after Agriolimax agrestis, the commonest slug, and I found
that in fully 20 per cent, the horse-shoe marking is complete, i.e. unites in front.
In some specimens there was only a faint indication of any marking at all ; in fact,
it is a feature which is not by any means constant. I noticed also that in those
20 per cent, in which the black pigment extends all round the groove, the general
body-colour is darker than in the others.

The body-colour in this species varies from yellowish brown to dark brown,
the sides getting lighter towards the foot. The inter-space between the wrinkles
is generally marked by darker pigment, and the mantle is granulated. The head
and tentacles are of a bluish colour, sometimes purple, and the keel is almost
always lighter than the body-colour on each side of it.

The largest specimen taken measured 65 mm. long, by 10 mm. broad.
Moquin-Tandon's (26) Limax marginatns, which is probably this species, never
exceeds 60 mm. in length in France.

Anatomy (Plate LVTL, fig. 30). — There are the four convolutions of the intestine
as in Agriolimax, but without a ccecum. The upper portion of the reproductive
organs are like those of Agriolimax, but in the lower parts, important differences
appear. The receptaculum seminis (rec.) is very large, equalling the free oviduct
(ov.) in length. Its lower part is wide, but it becomes attenuated in its upper
portion. What appears to be the penis is in reality the portion of the sperm-duct
in which the spermatophore is formed (pat.); the lower portion only can be looked
upon as a penis (p.). Both penis and oviduct, as well as the receptaculum, open
into a short vestibule or atrium (Iv.) which, according to Simroth (38), is everted
during copulation. A number of large accessory glands (ac.) also open into the
vestibule by means of delicate ducts.

Reproduction. — The fact that hardly any of the text-books referred to, give a
description of the eggs of this species shows that they have rarely been observed.
Although I kept a large number of specimens in captivity from the middle of
September to the end of the year, none of them deposited eggs. Simroth (38) is
the only author who refers to the ova of Amalia marginata, which is either the
same or a closely allied species to ours. He states having observed them at the end

Scharff — On the Slugs of Ireland.

533

of March, and that they measure 6 mm. by 5 mm. They are, therefore, about the
size of those of L. maximus, and very much larger than one would expect. I have
met with a good many specimens of the slug, about 15—20 mm. long in July, so
that the deposition of eggs in Ireland probably takes place in April or May. The
young ones do not differ to any appreciable degree from the adults. I saw no
half-grown or young specimens during winter, so that at any rate the reproduction
of this form seems to differ from that of most other slugs, and in all probability
it lives for more than one year.

Habitat. — Simroth gives limestone rubble (kalkgeroll) in mountainous districts
as the abode of the A. marginata. The habitat of our A. carinata is totally different.
It is one of the commonest garden slugs in Dublin. It is very gregarious, and
one often finds a number of them close together in worm-burrows, or at the root
of delicate plants. They are, like all slugs, fond of stiff clay soil, which keeps
the moisture so much longer than sandy soil, and which, owing to the numerous
worm-burrows, gives them better shelter. They spend the day underground,
and come out at night in damp weather, but they often drag bits of stalks
underground to feed on at their leisure. In the open country I have met with
them everywhere, but only locally. They are widely distributed. Miss Warren
tells me that this species is rare in Sligo, whilst A. gagates is common, but I have
received a large number of A. carinata (rather dark ones) from the Aran Islands,
county Galway, and it probably occurs everywhere in the West. These did not
differ anatomically from our Eastern forms. It seems surprising that Clarke (3),
who was such an authority on slugs, did not meet with this species in the North
of Ireland, and only records it from Dublin, whilst Thompson (43) gives Monivea
and Clifden in county Galway, and Cork, as the localities where it occurred to him.

Food. — Simroth (38) believes that the German species of Amalia are carni-
vorous. Although the Irish A. carinata is carnivorous at certain times, it is
generally a most determined vegetable feeder, and, I believe, runs Agriolimax
agrestis very close in being the most voracious and destructive of slugs.

As I mentioned before, I have had specimens in captivity for several months,
and I have had good opportunities for observing its habits in the garden. I find
that it is especially fond of leaf stalks and bulbs, but it greedily devours green
leaves. The bulbs and stalks seem to suit them better when they are stale and
beginning to decay. Of the thirty or forty which I kept in a large tin box filled
with earth, and always supplied with leaves, bulbs, &c, about a dozen were eaten
by their companions, only the shells being left. Observing them very closely, I
noticed that only weak specimens, which seemed either old or seized by illness,
were devoured.

The more vigorous ones always spent the day underground, burying themselves
several inches deep. In the garden I noticed that many bulbs in heavy soil

534

Scharff — On the Slugs of Ireland.

entirely disappear. This would be commonly attributed to the nature of the soil,
but it is really due to the depredations of A. carinata. I find that in sandy soil
bulbs are less liable to be attacked by this species. Gain (10) states that A.
marginata (= carinata) took most of the different kinds of foods offered. I hope
this writer will publish a more detailed account of the nature of the food offered
than what has hitherto appeared.

General Distribution. — Great Britain, Germany, Switzerland, France, Austro-
Hungary, Greece, Italy, Spain, and Portugal.

Amalia gagates, Drap.

Limax gagates, Draparnaud, Table Moll., 1801. Amalia gagates, Heynemann,
Mai. Blatter, 1861. Limax gagates, Jeffreys' Brit. Conch., 1862.

(Plate LVL, fig. 9.)

Colour generally dark lead or light drab brown. Keel of nearly the same
colour as the rest of body. Interspaces between wrinkles and groove on mantle
without black pigment ; foot white, and slime watery. Receptaculum short and
round.

External Characters. — As I have stated in the synopsis, this slug is distinguished
from A. carinata by its colour, which is black, or, more correctly, dark lead.
There is also a brown variety, but even then the two species are readily distin-
guishable. In A. carinata the brown is always richer, being either a deep rich
brown or a bright yellow-brown, while in the variety of A. gagates it is always a
light drab-brown. Besides, the foot is always pure white, the skin delicate, and the
mucus watery. In A. carinata the foot is yellowish, the skin is thick, and the mucus
tough and sticky. Both species may be distinguished merely by the touch. Whilst
A. carinata feels like a sticky lump of fat, A. gagates, owing to its more watery
mucus, glides readily through the fingers.

In this species the horse-shoe shaped groove on the mantle is well marked, but
there being no black pigment, it is not so apparent as in the preceding one.

The mantle in A. gagates is almost of the same size as the body, whilst in
A. carinata it is only about three-fourths of the length. The keel in A. gagates is
much sharper than in A. carinata, and the interspaces between the body-wrinkles
have no black pigment, which in A. carinata gives it the speckled appearance.

The largest specimen I have seen measured 50 mm. by 6 mm., showing that
it is altogether smaller and more slender than the other Amalia.

Anatomy (Plate LVIL, fig. 31). — Full-grown specimens measure about 30 mm. in

Schaeff — On the Slugs of Ireland.

535

spirit. The various parts of the reproductive organs differ from those in A. carinata,
chiefly in being much shorter. The sperm-duct (sp.), the " Patronenstrecke " (pat),
and the receptaculum (rec.) are all shorter, in comparison with the same organs in
the preceding species. The receptaculum seminis (rec.) exhibits, perhaps, the most
striking difference, being more rounded, with a short stalk. There is generally
one accessory gland (ac.) opening into the vestibule, but sometimes there are more.
I have noticed in a brown specimen as many as four, whilst in another from the
same locality there was only one.

Reproduction. — The smallest specimens I have seen measured about 20 mm.,
and did not differ very materially in colour from the adults. A specimen kept in
captivity deposited eight eggs at the end of August. They were very delicate
and thin-shelled, adhering together by a glutinous mucus. They were slightly
oval in shape, and measured only 2 mm. long by lj? mm. broad. It is surprising
that there should be such a very great discrepancy between the size of the eggs in
the two species of Amalia.

Habitat. — This species is one of the rarest of slugs ; and I never found it but
in the open country, and only at all abundant in one spot, at Raheny, near Dublin,
in a field under heaps of decayed weeds. In the same place I obtained an
occasional specimen of the drab-coloured variety among the others. Later on I
found a few specimens at Kilruddery and Whitechurch, both near Dublin. I
received two specimens from Miss Warren, who found them in her garden at
Ballina, in Sligo ; and a dark one from the Aran Islands, along with a number of
A. carinata. Clarke (3), who first discovered this species in Ireland, states that in
the Queen's County, at La Bergerie, the brown variety is much commoner than
the black. He has taken the slug also in the counties of Galway and Mayo, it
being very abundant in the latter.*

Food. — Gain (10) states that this species took 83 per cent, of the different
kinds of food which were offered. I have not myself observed what it lived on,
but it seems probable that its chief natural diet consists in decaying plants.

General Distribution. — Great Britain, France, Italy, Spain, Portugal, Sicily,
Sardinia, the Balearic Isles, Egypt, Algiers, Morocco, the Azores, Madeira,
St. Helena, Ascension, South Africa (?), California (?), Bermuda, and, probably
introduced, in Brazil.

Genus IV. — Arion (Ferussac, 1819).

Body, nearly cylindrical, strongly wrinkled. Mantle, shagreened or granulate.
There is a caudal gland. Internal shell, not solid, but composed of a soft mass of
granules. Pulmonary opening in front of middle of mantle, and genital pore

* I have since taken it at Queenstown, county Cork.

536

Scharff — On the Slugs of Ireland.

situated close to it. There never is a well-marked keel except in young specimens.
The intestine has four convolutions.

The most apparent characteristic by which this genus may be distinguished
from the preceding ones are the presence of a caudal gland, and the fact of the
respiratory opening being situated in front of the middle of tlie mantle.

The caudal gland is easily visible externally (Plate LVL, fig. 10). Its opening
is situated at the very end of the body, and is triangular in shape ; the base of the
triangle being directed towards the head.

Another, perhaps, less noticeable feature is that of the reproductive pore,
which lies quite close to the respiratory opening, whilst we have seen that in the
other genera it is situated near the tentacles.

The mantle, or shield, in Avion is granulated as in the genus Amalia.

All the species of Arion are altogether broader in shajDe than any of the slugs
hitherto considered.

There never is, in Arion, a well-marked keel, and though we may, as in young
Arion hortensis and A. bourguignati, have slight indications of one, it is nothing like
what obtains in Limax, Agriolimax, or Amalia. The wrinkles are generally more
prominent in Arion than in the other genera.

As regards the internal structure of the genus Arion, I may mention in the
first place that there is no solid shell, but a soft mass of calcareous granules,
which, in some of the smaller species, may be somewhat firmer than in the larger
ones. Simroth (38) has pointed out, that whilst Limax, Agriolimax, and Amalia
utilize their male end-organs during copulation, in Arion the female end-portions
of the reproductive organs are used as penes. What is generally looked upon as the
penis in Arion is no such thing, there being no retractor muscle to it. The enlarged
end portion of the sperm-duct is used for the preparation of the sperm atophore
(sperm-case), and Simroth (38) has applied to it the term " Patronenstrecke "
(cartridge-portion).

There are four convolutions in the intestine, the first being the largest.

Synopsis of the Irish Species of Arion.*

A. — Margin of foot with transverse striae = A. ater, A. subfuscus.

I. — Wrinkles keeled and elongated = A. ater.
II. — Wrinkles flat and short = A. subfuscus.

* It is very difficult to give good external distinctions for the species of Arion, but the above will
be found fairly practical, if it be kept in mind that -wrinkles are a variable feature and that slugs must
be compared under similar atmospheric conditions.

Scharff — On the Slugs of Ireland. 537

B. — Margin of foot without transverse striae = A. hortensis, A. bourguignati,
A. intermedins.

I. — Foot coloured = A. hortensis, A. intermedins.

a. Wrinkles flat = A. hortensis.

b. Wrinkles with conical spikes = A. intermedins.

II. — Foot white = A. bonrgidgnati.

Arion ater, L.

Liraax ater and L. rufus, Linnd, Syst. Nat. 1758. Arion empirieorum, Fe'russac,
Hist. Moll. 1819. Arion ater, Jeffreys, Brit. Conch. 1862.

(Plate LVL, figs. 10-16).

Colour very variable, but generally either brown, black, or red, in adults ;
and either light red or yellow in young ones ; wrinkles very long behind middle of
mantle, and sharply keeled. Foot generally yellowish, but never white ; head and
tentacles dark violet.

Synonymy. — Many Continental authors have adopted for this species Fe'rus-
sac's (8) name of A. empirieorum, chosen by him because he thought a new name
would avoid the confusion arising from Linnets adoption of two designations,
viz. " ater" and " rufus" for varieties of the same species. According to the
British Association Code of Rules, however, which is observed by British zoolo-
gists, the oldest name or the one standing first on a list shall be used, irrespective
of the suitability of the name.

External Characters. — This species is the most variable of our Irish slugs. During
youth the number of variations are much larger than in adults, as they almost all
darken with age, becoming more uniform in colour.

In Ireland I have up to now met with six very distinct varieties of the adult
slug, viz. brown, black, claret-red, salmon-red, olive, and black with yellow
sides. In some of these the foot may remain unaffected by the colour, whilst in
others the foot becomes more or less coloured too, but I think that is not a point of
any importance. The brown variety (Plate LVL, fig. 10) is perhaps the commonest
(in the gardens about Dublin, at any rate).

The margin of the foot, in all these varieties, is transversely striated, by which
character this slug may be distinguished from all other species of Arion except
A. subfuscus.

The wrinkles are useful in discriminating between A. ater and A. subfuscus.

TBA.NS. EOT. DUB. SOC, N.S. VOL. IT., PART X. 4 F

538

Scharff — On the Slugs of Ireland.

In the former the wrinkles on the back, just behind the mantle, are very long, and
sharply keeled, whilst in A. subfuscus they are hardly half as long, and flat.

Too much importance, however, should not be attached to the shape of the
wrinkles. Anyone who has kept this species in captivity can see for himself that,
by carefully sprinkling the box in which the specimens are confined with water,
the body-wrinkles after a while become more and more flattened out. A specimen
which may have had all its wrinkles standing out sharply from the body, in a dry
atmosphere, appears quite changed after it has been imprisoned in a damp tin box
for a couple of hours. There are naturalists who have manufactured new species
of Avion merely by the different shapes of the wrinkles ; but a little practical
observation shows how much they are worth. An adult of A. ater cannot be mis-
taken for A. subfuscus, but a }'oung one might, and indeed has been by most
writers. A rough and ready method of discriminating between the two species is
to give them a tap on the head. A. ater will almost immediately draw itself
together, and resting on its foot, the arched body will appear nearly equal in
length and breadth (Plate LVL, fig. 11). Another tap now will, in almost every
case, even in very young specimens, cause the animal to rock about from side to
side. This most peculiar motion, which is often continued for several minutes, has
never, to my knowledge, been observed in any other slug. A similar tap applied to
A. subfuscus will merely cause the animal to shrink up, but it will never assume
the characteristic hunched position of A. ater, nor will any tapping produce the
swaying movement.

The margin of the foot is very often of a colour different from the rest of the
body ; thus in brown specimens the margin may be brick-red. On the Continent
specimens of a similar brick-red tint covering the whole body are extremely
common, and in central Europe the large majority are of this colour. (This will
be referred to again in the Chapter on Colour.) I have never seen an adult brick-
red specimen in Ireland.

The head and tentacles are, as a rule, of a dark violet colour. There is no
trace of a keel, the back being perfectly rounded.

This species assumes much larger proportions on the Continent than it does in
Ireland. The largest I have seen near Dublin measured 90 mm. by 10 mm. On
the West Coast specimens of that length, but rather broader, are common. The
average size for a full-grown specimen on the East Coast, however, is 60 mm.
by 10 mm.

The nature of the mucus varies in proportion to the severity of the stimulus.
As a rule colourless, it becomes orange-yellow when the animal is much irritated,
and sometimes I have seen it milky like that of Agriolimax agrestis.

Anatomy (Plate LVIL, fig. 32). — Detailed accounts of the anatomy of this
species have been given by Lawson (18), Nunneley (31), and others. I have

Schakff — On the Slugs of Ireland.

539

examined specimens from Norway and the different parts of Ireland, and find that
there is less difference between the East Irish and Norwegian than there is between
the West and East Irish.

The colour of the hermaphrodite gland (hg.), generally of a light brown,
varies according to the colour of the body. The hermaphrodite duct (lid.) is well
convoluted. The free oviduct (ov.) opens into a vestibule as in Amalia, but there
is in Arion ater an additional glandular lower vestibule (Iv.) which has by Law-
son (18) been incorrectly named cloaca. The upper vestibule (uv.) or atrium he
distinguishes as the " egg-sac."

The sperm-duct (sp.) ends in what used to be regarded as a penis, but which
Simroth (38) has shown is only the enlarged lower portion of the sperm-duct {sp.)
in which the spermatophores or sperm-cases are formed. The receptaculum (rec.)
and the " Patronenstrecke " (pat.) of the sperm-duct (sp.) opens into the lower
portion of the upper vestibule (uv.).

Both the oviduct (ov.) and the duct of the receptaculum are provided with
powerful retractor muscles (rm.), which in West Coast specimens are attached quite
close to the receptaculum and the upper portion of the oviduct, respectively, whilst
in East Coast forms these same muscles are almost invariably attached much lower
down to the same structures. Of course this alone may not be of much importance,
but coupled as it is with differences in colour and length of life, the West Coast
forms constitute what we may at present regard as a striking variety of A. ater
which may become further modified in time. I propose to reinvestigate this form
when I have collected more material in the West.

Reproduction. — The eggs are laid chiefly in August and September, in clusters
averaging about fifty in number. I have frequently observed them in fields under
heaps of hay and in gardens under stones. They are deposited freely in captivity.
They adhere only very slightly to one another, and may be easily distinguished
from any of those previously described by their remarkable hardness. They feel
quite solid, and owing to their calcareous shells are perfectly opaque. They have
a long diameter of 4 mm. and a short one of 3 mm.

I said above that reproduction takes place chiefly in August and September,
but a few specimens, undoubtedly, deposit eggs earlier, for I have seen quite
young ones in August, and as the eggs take about 4 to 6 weeks to develop, they
must have been deposited in June.

Throughout the winter large numbers of young ones are to be met with in the
garden, and frost does not seem to affect them very much. These young speci-
mens (figs. 13 and 14) are invariably of a very light yellow or red — never dark.
Generally well-defined black lateral bands run along each side of the body, and are
continued on the mantle, ending at its anterior margin ; and all have dark-
coloured heads and tentacles. I have no doubt that these young forms, which are

540

Scharff — On the Slugs of Ireland.

about 30 mm. long in March, reach their maturity in the following autumn, and
I quite agree with Simroth (38), who fixes the limit of age in A. ater at one
year.

In the month of March the portion of the back and mantle between the lateral
bands becomes darker, a condition which is well seen in figs. 11 and 12; and in
that case a narrow light stripe is left between the dark portion and the bands.
But in some cases the back darkens uniformly, producing forms which have been
described by Roebuck as var. bicolor (fig. 15). I have found a half-grown form at
Whitechurch, near Dublin, in which the back remained light, whilst the sides
darkened (fig. 16). Similar young forms of the var. bicolor have been described
by Simroth (38) from the shores of the Baltic, and it is remarkable that every
instance of their occurrence is in close proximity to the sea. The light sides in
these specimens remain light throughout life. At Raheny, near Dublin, where I
have collected extensively last September, fully 30 per cent, were black above
with yellow sides, the remainder being entirely black with olive margin of
foot. All these had fully-developed reproductive organs. At Howth, Mr. Red-
ding has taken them with brilliant orange sides (fig. 15). In both cases the
specimens were found almost within reach of high tide. Only in one instance
have I seen this variety further inland in several specimens which were kindly
given to me by Mr. A. G. More, from his garden at Rathmines. This lies fully
three miles from the sea, but it may be that they found their way to the gardens
with plants from the sea-side.

This disposes of the A. ater from the East Coast of Ireland. On the West
Coast the same species forms a very remarkable variety, possibly owing to the
difference of the meteorological conditions. If we look at Scott's (37) latest report
on the variability of the temperature in the British Isles, we find that during fifteen
years in Valentia Island, the thermometer only descended below freezing point six
times. In summer, during the same period, it only once rose above 70° F. (=21° C).
There is in fact probably no place in Europe where such an equable climate exists
as on the South-West Coast of Ireland.

As a result of these favourable meteorological conditions, adult forms of A. ater
survive the winter, but apparently do not develop reproductive organs in that
period. I received a large box of specimens, 80 mm. long, from the Aran
Islands in November. Their body cavity was almost entirely filled with a huge
liver and intestines, whilst the generative organs were like those of an ordinary
half-grown specimen. Again, in May, I collected everywhere in the mainland of
Kerry, and on Valentia Island, numbers of specimens considerably larger than
our Dublin full-grown forms, but again with hardly a trace of any reproductive
organ. Among these an olive-coloured variety is very common, and also one of a
cinnamon-red ; neither of these is banded. Besides these, rich brown forms, like

Scharff — On the Slugs of Ireland.

541

those on the East Coast, also occur. Those from the Aran Islands were almost
all pitch black.

I only found two specimens with fully developed reproductive organs in my
collection, and these were sent to me in August by the Rev. A. H. Delap, from
the Skelligs Eock, off Valentia. Thus we probably have the same period of
reproduction as on the East Coast, but the specimens either live for two years, or
for a year and a-half. The latter seems to me more probable, and we should, in
that case, have a second period of reproduction in the early months of spring on
the West Coast.

Habitat. — This species is found everywhere in company with Agriolimax
agrestis, both on the mainland and many of the islands on the West Coast. In the
garden it is one of the commonest forms. In my own garden I have never seen
an adult of any other colour than a rich brown (fig. 10). Similar brown slugs I
have noticed as very abundant on the West Coast. In woods and fields near
Dublin I have hardly ever seen this variety. In the Dublin Mountains, at Killakee,
all the adult forms I obtained were of a dark claret colour ; they resembled very
much the fallen pine-needles that covered the ground, and it seemed to me a case
of protective colouring.

On the West Coast I have collected at Cahirciveen, Derrynane Bay, and other
places in the Co. Kerry, and most specimens were either brown or olive-coloured —
sometimes of a salmon-red — and the ground being boggy, again resembled the
colour of the slugs. It has been remarked by many observers, and it agrees with
my experience, that this slug is more often seen crawling about in the daytime
than others. I have especially noticed this fact on the West Coast, where, of
course, the climate is exceedingly damp, but it struck me also in the forests of
Germany, where one sees so many large red-coloured A. ater.

Food. — A. ater is undoubtedly a voracious vegetable feeder, preferring decaying
chlorophyllaceous plants to fresh ones. I have kept them on campanula leaves for
a long time. Kew (17) kept this species in captivity from May to October, during
which time twenty-six different substances were eaten. One slug lived on a news-
paper for some time. He says — "The dead bodies of Arion subfuscus, A. hor-
tensis, Limax maximus, L. Jlavus, and L. agrestis, a dead Unio, freshly turned
pupae of Adimonia tanaceti, a small part of the abdomen of a dragon-fly {Diplax
slriolata), leaves of lettuce, Scabiosa sueeisa and Solatium nigrum, flowers of Pedi-
cularis sylvatica, Ranunculus flammula, R. acris, R. repens and R. bulbosus, and the
lichens Evernia prunastri and Ramalina farinacea were readily fed upon. Poly-
podium vulgare, Eryngium maritimum, and berries of Arum maculatum were taken in
small quantities and with evident reluctance, as also was Pears' soap."

Thompson (43) noticed two specimens of this species busily engaged devouring
a snail (H. aspersa) which appeared to be freshly killed.

542

Schakff — On the Slags of Ireland.

We thus see that although A. ater is on the whole a vegetable feeder, it is not
particular as to its choice of food, and is always ready to eat almost anything that'
comes within reach.

General Distribution, — Great Britain, and throughout continental Europe,
Algiers (?), Azores (?), Madeira, and Iceland.

Arion subfuscus, Drap.

Limax subfuscus, Draparnaud, Table Moll., 1801. Arion ater (pars), Jeffreys,

Brit Conch., 1862.

(Plate LVL, figs. 17-19.)

Colour either yellowish or light gray ; never brown or black. The wrinkles
short and flat. Margin of foot white, with gray transverse strise. Thick yellow
slime on body, chiefly near head and tail. Foot and sides of body generally white ;
sometimes yellowish.

Synonymy. — In such text-books as Jeffreys (16) and Forbes and Hanley (9)
this species is grouped under the varieties of A. ater, although it had long before
been described as a distinct form by Draparnaud (5). I believe that Midler's
(28) A. flavus is an immature form of A. subfuscus, and not identical with
Simroth's (38) A. minimus, the latter never growing longer than one inch, whilst
Miiller gives 1^ inch as the size of his slug.

External Characters. — Three varieties of this slug are found near Dublin which,
although they do not, as far as I have been able to ascertain, differ anatomically,
show considerable external differences. We may, indeed, regard them as species
in process of formation. I have had too few specimens to come to a definite
conclusion, and further researches may reveal new characters by which they can
be separated anatomically.

The typical A. subfuscus (Plate LVL, fig. 17) resembles A. ater in having the
margin of the foot transversely striated, and in having a dark head and tentacles,
which, however, are never as dark as those in A. ater. The sides are white, and
have a semi-transparent appearance like a wax candle. The margin of the foot,
and the foot itself is white, the former with delicate gray cross-bars. There is
no variety of A. ater with a white foot or white sides, and this distinguishes the
typical A. subfuscus at once. The upper surface is dark gra}^, becoming lighter
towards the very distinct lateral bands. The whole of the back and mantle is
almost always covered to such an extent by a thick reddish-yellow mucus, as to
obscure the gray colour and make it appear reddish-brown. The mucus is most
intense in colour on the anterior portion of the mantle, and near the caudal gland.

Scharff — On the Slugs of Ireland.

543

To show that this mucus has nothing to do with the real colour of the slug
one need only wrap it up in a piece of blotting paper, and roll it about for a
moment, when all the mucus will be soaked up. The slug then appears in his
natural costume, which is composed of white and a bluish-gray, without any trace
of a yellow or red pigment in the skin.

If we subject the two varieties (Plate LVL, figs. 18 and 19) to the same treat-
ment we get a very different result. The first (fig. 18), which, by the way, is not
the A. brunneus mentioned by Lehmann (20) and Simroth (38), has no lateral bands,
but is rather darker on the back than at the sides. It is a yellow slug, but on the
mantle we again find the peculiar reddish mucus, and if the latter is soaked up by
blotting paper, we have an entirely yellow slug, and the yellow is due to a
pigment investing the skin in small granules. Moreover, the space between the
wrinkles is of a bluish colour. The second variety (fig. 19) is entirely yellow,
with a lateral band on the back. The margin of the foot in both these varieties
is yellow, the yellow colour extending also to one-third the breadth of the foot on
each side.

I found the typical form of A, subfuscus generally between 40 and 45 mm. in
length, whilst adults of the first variety were as a rule rather smaller, viz. 35 to
40 mm. Of the second variety I obtained only one specimen, whose reproductive
organs, although not fully developed, showed that it was more nearly allied to A.
subfuscus than to A. ater. Recent investigations into the anatomy of the Arionidce
such as those of Pollonera (33) and Simroth (40) may throw light on the affinities
of this species, which for the present I must regard as a variety of A. subfuscus
more material is available. My specimen was 55 mm. in length.

The wrinkles in all these slugs differ from those in A. ater in being much
shorter, which is especially well seen in the wrinkles just behind the mantle.
They are much flatter than those in A. ater, although one has to guard against
the influences of temperature in comparing these in different slugs, as I have had
occasion to point out under the heading of A. ater. The slime is abundant and
clear, and must be distinguished from the intensely yellow mucus which is
until produced by the mucus glands on the back and mantle of the slug.

Anatomy (Plate LVII., fig. 33). — The internal organization of this species differs
little from that in A. ater, but all the different parts, of course, are smaller. The
ovisperm-duct (ps.) is shorter in proportion than in A. ater. As in the latter there
is no penis, the sperm-duct (sp.) ending in a " Patronenstrecke " (pat.) in which
the spermatophores are produced. This portion opens into the lower part of the
duct of the receptaculum (rec), which, in its turn, opens directly into a lower
glandular vestibule (lv.), the upper vestibule being absent. The genital retractor
muscle (rm.) is attached to the oviduct (ov.) much higher up than in A. ater (see
fig. 32).

544

Scharff — On the Slugs of Ireland.

Reproduction. — I found the eggs of the typical A. subfuscus commonly at
Raheny, near Dublin, at the end of August, and the species also bred freely in
captivity. The eggs were mostly about 3 mm. long by 2% mm. broad, and semi-
transparent, much clearer than those of A. ater. Similar eggs, but rather smaller, viz.
2i mm. by 2 mm. were deposited in captivity by the variety shown in fig. 18. The
eggs number generally about twenty in a cluster, and were seen from the middle
of August to the middle of October. The young forms were not observed, and I
have not sufficient data to express an opinion as to its limits of age.

Habitat. — I have taken the typical form of this species very abundantly at
Raheny, Co. Dublin.* They were found in fields close to the sea where horses
were kept and fungi abounded in autumn. Wherever there was any horse-manure,
numbers of A. subfuscus were sure to be close by. But I also got them under
decaying heaps of weeds in another field in the neighbourhood.

The difference between those found among the manure, and those occurring
among the weeds, first drew my attention to the absence of yellow in the skin of
these slugs, the colour being entirely due to the mucus. Those found among the
weeds secreted hardly any of the yellow mucus, and being white with gray backs,
differed at first sight very much from the vividly-coloured specimens found
previously.

The first variety (fig. 18) was found in a small pine wood on Howth Hill, near
Dublin, about 300 feet above the fields referred to. Similar specimens were
obtained on Bray Head, in the Co. Wicklow, and, along with the variety fig. 19,
at Killakee in the Dublin Mountains.

Food. — These slugs seem almost entirely to subsist on fungi, chiefly of the
genus Russula ; but they do not despise the poisonous Agaricus muscarius, which
proves deadly to flies and other insects. I once observed two specimens eat a
fallen poplar leaf in a wood, although plenty of fungi were quite close to them ;
but it was only after some days that specimens in captivity gnawed at the green
leaves of Campanula. Simroth (38) found them, especially in the north of Ger-
many, feeding on all kinds of fungi, and observes that they never colour spirit
green, which proves that they do not live on chlorophyllaceous food.

Kew (17) saw A. subfuscus devour a dead specimen of its own species, and also
an Amalia marginata (= carinata). In captivity, he observes, they eat bread and
leaves of lettuce freely, also the leaves of Solanum dulcamara when decomposing.
A fungus {Phallus imjmdicus) was eaten voraciously, but the slugs then died,
probably owing to the foetid smell given off by it.

General Distribution. — Great Britain, continental Europe (except Spain and
Portugal), Iceland, and Greenland (?).

* I also found it at Glengariff, Co. Kerry.

Scharff — On the Slugs of Ireland.

545

Arion hortensis, F^russac.

Arion hortensis, Ferussac, Hist. Moll., 1819. Arion hortensis (pars), Jeffreys,

Brit. Conch., 1862.

(Plate LVL, fig. 20.)

Colour of body generally dark gray or light brown, with bluish-gray sides.
Lateral bands somewhat diffuse towards sides of body, always present, and con-
tinued to front of mantle. Foot always red, wrinkles broad. The calcareous
grains composing shell often more aggregated than in other species. Receptaculum
seminis round.

External Characters. — A typical form of this slug is at once recognized from
other species by the red colour of the margin, as well as the sole, of the foot. But
the intensity of this colour is subject to a good deal of variation, and in many cases
the foot is more of a yellowish colour, with just a tinge of red, while sometimes
only a faint indication of colouring remains. In such cases A. hortensis might well
be mistaken for one of the other species. By a little practice, however, we can
soon detect other distinguishing characters.

If we take an A. hortensis of 20 mm. in length, and compare it with specimens of
A. ater (PI. LVL, fig. 16) A. bourguignati (PI. LVL, fig. 21), and A. intermedins (Plate
LVL, fig. 22) of the same length, the little conical wrinkles will at once eliminate
the latter. From A. ater the specimen of A. hortensis will be distinguished by its dark
colour, young ones of the former being always light-coloured ; the wrinkles, more-
over, in A. ater are longer and broader. Sometimes A. hortensis is remarkably like
A. bourguignati, but apart from the wrinkles, which are broader in the former, the
lateral bands are somewhat diffuse towards the external edge, as if they had been
touched by a wet brush, whilst in A. bourguignati their edges are well defined.

If spirit specimens of the same size are taken, which sometimes have lost all
trace of colour, the wrinkles must decide, and, of course, as a last resource, the
anatomy. If we measure the width of the wrinkles just behind the mantle, we find
that in A. ater rather more than one, in A. hortensis two, and in A. bourguignati three
wrinkles go to the millimetre.

So much for comparison. As for the general colour of this species, I find that
two distinct varieties are as a rule found in the garden. The back of the body and
mantle in the first is of a dark gray, becoming lighter towards the lateral bands.
Below these the body is of a light, sometimes bluish-gray colour.

In the second variety, which was much more numerous in my garden in Sep-
tember, the back of body and the mantle were as if dusted over with fine yellowish

TRANS. HOT. DOB. SOC. N.S. VOL. IV., FART X.

546

Scharff — On the Slugs of Ireland.

brown powder, so as to produce a light brown tint (Plate LVL, fig. 20). Below the
lateral bands the body colour is a light brownish-gray.

According to Simroth (38) the light colour is produced by warmth, and the dark
by cold ; but whether this explanation holds good in the case of the two varieties
of A. hortensis occurring in the same locality at the same time of year, seems to
me extremely doubtful. However, I shall refer to this again in the chapter on
colour.

The largest specimens of this species were 35 mm. long. The mucus is yellow
and somewhat sticky.

Anatomy (Plate LVIL, fig. 34). — As in the other species the characteristic part
of the anatomy is to be found in the lower portion of the reproductive organ. As
in A. ater there is an upper (uv.) as well as a lower vestibule (lv.). The free
oviduct (ov.) is long and widened in its lower part. The sperm-duct (sp.) ends in
a somewhat swollen " Patronenstrecke " (pat.), whilst the long-stalked recep-
taculum (rec.) is round. The genital retractor muscle (rm.) divides into two
bundles, one going to the duct of the receptaculum, the other to the oviduct.

The calcareous grains under the mantle are, in this species, often aggregated so
as to form a rudimentary shell, which, according to Lessona and Pollonera (21) in
Italian specimens is well developed.

Reproduction. — I kept about fifty specimens in captivity from the middle of
September to the end of October, but no deposition of ova took place, nor did I ever
see ova that I could refer to this species. Simroth (38) had some eggs deposited
by captive specimens, which were perfectly round and clear, with a diameter of
2 mm.

It is remarkable that very young specimens of this species have a keeled back,
but this keel, not being different in colour from the surrounding wrinkles, is not
very easily seen — and it entirely disappears in half-grown specimens.

It seems to me probable that the deposition of ova takes place in the early
months of summer or spring, but additional observation is needed also with regard
to the duration of life in this species. All the specimens I have seen during winter
were pretty large, mostly half-grown, which leads me to suppose that no deposition
of ova takes place during autumn.

Habitat. — Simroth (38) states that A. hortensis is a South European form, and
probably does not occur north of the 52° of latitude. However, he has since
examined the Irish forms, and pronounced them identical with the German ones,
so that we may safely conclude that it does extend considerably farther north than
Simroth anticipated.

The same author states that he has never met with a specimen anywhere but
in gardens, churchyards, and within villages.

In Ireland, although also very common in gardens, it certainly has a wider

Scharff — On the Slugs of Ireland.

547

range. I have found it in a wood at Kilruddery, in Co. Wicklow; also at Killakee,
in the Dublin Mountains, and other places far removed from cultivated ground.

It seemed to me remarkable never to meet with the brown, or yellowish variety
in the open country — all were of a dark bluish-gray, and the foot always more
yellowish than red.

Although I did not find this species in Kerry, Miss Warren kindly sent me half
a dozen specimens from Sligo, and it has also been recorded by Thompson (43)
from the North of Ireland.*

Food. — I had great difficulty in keeping this species in captivity, and its
numbers diminished rapidly until they all died. Pieces of apple and Campanula
leaves were eaten, but neither appeared to be relished ; and I am inclined to think
that A. hortensis lives chiefly on decaying vegetation, as they are most numerous
in the garden among heaps of old weeds. I have never found it on fungi. Sim-
roth (38) believes that it is a vegetable feeder, and that it is especially partial
to heavy soil. Gain (10) also found that A. hortensis was rather sickly in confine-
ment, but he states that 60 per cent, of the foods offered were taken.

General Distribution. — Great Britain and Continental Europe, except Scandinavia
and Russia.

Arion bourguignati, Mabille.

Arion bourguignati, Mabille, Rev. et Mag. de Zool., 1868. Arion hortensis
(pars), Jeffreys, Brit. Conch., 1862.

(Plate LVI.j fig. 21.)

Colour light gray or reddish gray. Lateral bands on body continued to front
of mantle. Foot always white. Wrinkles narrow. A distinct keel in young
specimens. Receptaculum seminis elongate.

External Characters. — As I have pointed out above, this species is so much like
A. hortensis that the two species are still by many conchologists mistaken for one
another.

The brilliantly white foot is one of the best distinguishing characters, but by
the mere touch one is often able to discriminate between the two forms, as A. bour-
guignati is always much less slimy. The wrinkles are narrower, and its whole
appearance is more slender. Young specimens, as pointed out by Mabille (24), are
at once recognized by the keel which, owing to its white colour is rather conspicuous.
It is a somewhat smaller species than A. hortensis, the maximum length reaching
as a rule not more than 32 mm.

* I have since found it in Wexford and Queenstown, in the South, and in Connemara, in the "West of
Ireland.

4 G2

548

Schaeff — On the Slugs of Ireland.

As in the other, there are two varieties in colour, but in the garden I have never
met with the dark form. The young, both in the open country and garden, are
delicately gray, with a well-defined lateral band on each side of the body and
mantle. The colour remains the same in the garden forms as they grow up, but a
number of reddish pigment spots appear, which produce a general effect of tan-
colour. In the country specimens I have never observed this development of red
pigment, and the original gray colour merely darkens, so as to produce a dark-
gray slug.

Anatomy (Plate LVII., fig. 35). — Although this and the preceding species are
difficult to distinguish externally, anatomically A. bourguignati presents unmis-
takable characteristics.

The hermaphrodite gland (%.) is dark-brown and round. The free oviduct
(ov.) which is long in A. hortensis, is here quite short, whilst on the other hand, the
sperm-duct (sp.) is longer in A. bourguignati, and the " Patronenstrecke" [pat.) is not
swollen. But perhaps the most apparent difference between the two species is the
shape of the receptaculum (rec.) which in this species terminates in a long pointed
apex. A. bourguignati has only one large vestibule (lv.), viz. the lower, whilst in
A. hortensis there are two.

Reproduction. — I have not been able to observe the deposition of eggs in this
species, although large numbers of specimens were kept in confinement during the
months of September and October.

This and the almost complete absence of adults in September lead me to think
that reproduction takes place early in the summer. This agrees with Simroth's
(38) observations, who also found only half-grown forms during winter.

Habitat. — This species is not nearly so common as the preceding one, but still
it has a wide distribution in Europe. I have obtained it commonly in my garden
where the soil is heavy, and also among moss and under stones in the Dublin
Mountains. In Kerry I found it on Valentia Island and at Lough Caragh, whilst
Miss Warren sent me a specimen from Ballina, in Sligo.

I met with the largest specimens in June and July, but never in the daytime.
This, no doubt, accounts for the fact of its having been comparatively rarely met
with on the Continent, for Simroth (38) states that it is rare during summer,
whilst Mabille (24) speaks of it as " une espece d'hiver."

Food. — Like the last, this species does not thrive in captivity, and although
they will nibble at pieces of apple and rhubarb stalk, they appear to me to prefer
decaying vegetation. I never found it among fungi, but in my garden, when it
emerged from the ground early in the evening along with Agriolimax agrestis, it, as
a rule, remained on the ground, whilst the latter ascended the pea plants, and did
a great deal of damage by eating the young shoots and flowers. It seemed to me

Schakff — On the Slugs of Ireland.

549

as if A. Bourguignati preferred to feed on the fallen flowers which were partially
decomposed, instead of attacking the living parts of the plant.

Gain's (10) experience is very different from mine, for he says : " This slug ate
exactly one-half of the foods given, and thrives and breeds freely in confinement."

General Distribution. — Great Britain, and continental Europe, except Spain and
Portugal, and Siberia ( ? ).

Arion intermedius, Normand.

Limax intermedius, Normand, Descr. lam., 1852. Arion hortensis (pars),
Jeffreys, Brit. Conch., 1862. Arion minimus, Simroth, Zeitschr. wiss. Zool, 1885.

(Plate LVL, figs. 22, 23.)

Colour light yellow or gray, with abundant yellow slime chiefly near head and
caudal gland. Wrinkles with little conical spikes. Lateral bands either absent or
very faint. It occurs chiefly on fungi.

Synonymy. — Simroth (38) was the first to re-establish on anatomical grounds the
claims of this form to rank as a distinct species. Finding no satisfactory descrip-
tion of any species corresponding to his own, he called it Arion minimus, which name
I temporarily adopted in a preliminary notice sent to the Conchological Society
(36). Since the publication of his monograph, Simroth consulted the writings of
older authors, such as Miiller (28) and Nielsson (29), but as their A. flavus seemed
to have been a larger slug, probably a young A. subfuscus, he thought his name
(A. minimus) should be retained. Gmelin (11) and F^russac (8) merely repeated
Miiller's description without apparently having seen the slug. Among Moquin-
Tandon's (26) uncertain species, we find A. flavus again, and there is no doubt
that the author of the " Mollusques terrestres et fluviatiles de France " really had
specimens of our slug before him, which he believed was the same as that referred
to by Miiller, Gmelin, and F^russac. But as Pollonera (32) has pointed out, the
priority rests with another French author, viz. Normand (30), who described the
same species under the name of A. intermedius three years before him.

External Characters. — This is the smallest of our Arions, and the only one
besides A. ater which when at rest assumes the peculiar arched position (fig. 23).
When examined in that attitude with a pocket lens we find that the wrinkles pro-
ject in the shape of little conical knobs, and these give the slug that glittering
appearance by which it is easily recognized from the other species.

The colour of A. intermedius is almost always white, or sometimes light gray,
but owing to an abundant yellow mucus it often appears canary-yellow, especially
near the caudal gland. The foot also is yellow, due to the same cause. The head
and tentacles are dark gray.

550 Scharff — On the Slugs of Ireland.

The bands are sometimes completely absent, but when present, they are very
faintly marked and diffuse, both on the body and mantle. I think the nature of
the lateral bands and the wrinkles are the two most characteristic features in
this slug.

Compared with A. Bourguignati, for which dark specimens might be mistaken,
the touch alone will help us to some extent, A. intermedins being much softer, and
leaving a bright yellow watery mucus behind, whilst the former is thick-skinned,
with a sticky white mucus. The habitat will also distinguish the two species, as
they are never found in company.

Anatomy (Plate LVII., fig. 36). — The reproductive organs, as has been shown by
Simroth (38) approach those of A. subfuscus more than those of any other form.

The oviduct (ov.) is short and straight, the receptaculum seminis (rec.) round,
and the sperm-duct (sp.) scarcely swollen in the " Patronenstrecke " [pat). These
open into a large vestibule {lv.).

Reproduction. — The clusters of eggs which I observed very frequently in August
and September never exceeded twenty. The eggs are remarkably large for the
size of the slug, being 2 mm. long by \\ mm. broad. The young ones of 8 mm.
in length, which I bred in captivity, were of a light gray, owing to the intestine
being visible through the semi-transparent walls of the body. The head was
of a delicate gray, and no bands were visible on the body or mantle. Still younger
ones, of 3 mm. long, were of a very light red, with violet tentacles, and had
emerged from the egg three weeks after their deposition. Their limit of age has
been determined by Simroth (38) as not exceeding one year. I myself found
adults up to the middle of October, but not by any means so commonly as during
August and September.

Habitat. — This slug is never met with in the garden or on cultivated ground.
I found it for the first time last August in a field under a heap of decayed weeds at
Raheny, near Dublin, in company with Arion ater, A. subfuscus, Amalia gagates, and
Agriolimax agrestis. Shortly after, I obtained numerous specimens close by feeding
on common mushrooms (Agaricus) and fungi, which had appeared in the fields.

In the Earl of Meath/s demesne at Kilruddery, county Wicklow, this slug is
common ; also at Killakee in the Dublin Mountains. In fact, wherever there are
fungi one is sure to find it, but, like A. subfuscus, it takes green food pretty freely
in captivity. No doubt, A. intermedins has a wide range, but up to the present I
have only taken specimens in the neighbourhood of Dublin, whilst one was sent
me by the Rev. A. H. Delap, from Lough Caragh, in Kerry. This latter was of a
uniformly dark gray colour.*

Food. — The nature of the food has already been referred to above. A. inter-

* I have since taken them in Connemara, in the "West of Ireland.

Schaeff — On the Slugs of Ireland.

551

medius is a most typical fungus-eating slug, and I have chiefly found them on
species of Russula, Agaricus, and Clavaria.

General Distribution. — Great Britain, Scandinavia, Germany, France, Italy (?),
and probably introduced in New Zealand.

Genus V. Geomalacus, Allman, 1846.

Body sub-cylindrical; pulmonary opening on front of middle of mantle. Genital
pore near base of upper tentacles. Caudal gland opening by transverse slit. There
is a solid internal shell.

This genus was established by Allman (1) to include the most interesting of
Irish slugs.

At first sight a Geomalacus looks very much like an Arion, but the end of the
body which in that genus is pointed, and contains the longitudinal opening of the
caudal gland, is, in Geomalacus, rounded off, so that the caudal gland opens by a
transverse slit between body and foot.

The reproductive pore or genital opening lies close to the tentacles, as in the
genus Limaz, whilst in Arion, as we have seen, it is situated near the pulmonary
aperture.

As for the anatomy, the distinctive characters of Geomalacus maculosus will
be mentioned below, so that it remains only to be said that there is a solid internal
shell, something like that in Limaz, but very different from the calcareous particles
found in Arion. Only one species has hitherto been found in Ireland, and it occurs
nowhere else in Europe, except in North-western Spain and North Portugal. Two
other species of Geomalacus (G. oliveirae and anguiformis) have been found in
Portugal, but only short descriptions of their external characters have appeared
as yet.

Mabille (23) in a Paper on the genus Geomalacus, described several species of
French slugs, which he believed to be of this genus, but it has already been clearly
demonstrated by Heynemann (13) that this view is entirely without foundation.
They really belong to the genus Arion.

Geomalacus maculosus, Allman.

Geomalacus maculosus, Allman, Ann. and Mag. Nat. Hist. 1846. Geomalacus
maculosus, Jeffreys, Brit. Conch. 1862.

(Plate LVI., fig. 24.)

Colour dark gray, with light yellow or whitish spots on body and mantle.
Ezternal Characters. — The figures given by Heynemann (13) in his excellent

552

Scharff — On the Slugs of Ireland.

Paper on this species, are much better than Allman's original drawings, in spite of
the fact of the latter having been executed by so able a draughtsman as the late
Mr. Du Noyer. Du Noyer's figures are pretty, but idealized. The only point in
Heynemann's figures which I take exception to is the caudal portion of the body.
This should not be so flat, but more raised as in my figure 24. Forbes and
Hanley (9), Jeffreys (16), and others, seem to have merely copied Allman's
figure.

This slug was discovered in the county Kerry, in the autumn of 1842, by the
late William Andrews of Dublin, who placed it in the hands of Dr. Allman ; and it
was first exhibited at a meeting of the Dublin Natural History Society in January,
1843. The skin is always smooth and shiny, and not black, but of a dark gray
colour.

Both on the mantle and back there are a series of yellowish-white or yellow
spots. These seem at first sight quite irregularly placed on the body, but Sim-
roth (39) has drawn attention to the fact that on closer inspection there appear
traces of distinct longitudinal bands, as in Avion. In most cases, indeed, I have
observed these very well, but in others the banding is very difficult to demonstrate.
The margin as well as the sole of the foot are of a dirty white. The tips of the
tentacles are cylindrical, whilst in the genus Avion they are round. The mucus is
transparent and limpid. The largest specimen measured about 55 mm. in length.

Mabille (23), in his Paper on the genus Geomalacus, referred to on p. 551, has
attempted to set up a second species, which he calls G. andvewsi. His assumption
is based on Allman's original description, who mentions, besides the common form,
a white-spotted variety. Mabille believed that this meant a white, spotted variety,
i.e. a white slug with black spots, and, astounding as it may appear, proceeded on
these grounds to describe it as a new species.

Anatomy (Plate LVII., fig. 37). — Heynemann(13) does not deal with the anatomy
of this slug, excepting in a reference to the shell and the tongue, neither of which
is of very great importance. The latter is very much like that of an ordinary
Avion, but the shell is firm and regular like that of a Limax.

The fact that the calcareous particles often congregate together in Avion
intevmedius, and form a kind of irregular shell, has induced French authors, such
as Mabille (23) and Baudon (2), to start the idea that this slug must be a
Geomalacus ; but the shell in the genuine Geomalacus is of a very different nature.
The intestine resembles that of Avion, but the reproductive organs differ widely.

The penis (p) is formed by the enormously developed duct of the receptaculum
seminis (vec.), and not by the oviduct, as in Avion. There is a long retractor
muscle (rm.) attached to the penis at the part where the sperm-duct opens into it.
The sperm-duct (sp.) is very much longer than in any Avion, whilst the ovisperm-
duct (os.) is shorter.

Scharff — On the Slugs of Ireland.

553

Reproduction. — I found a few half-grown specimens along with the adults last
May, but did not observe the eggs. Dr. Simroth very kindly sent me the proof-
sheet of his large Memoir on the Slugs of Portugal and the Azores (40), and in it I
find a statement that a Signor de Silva e Castro had seen the eggs. They were
quite transparent, and very large, measuring from 5 to 7 mm. long, and 3 mm.
broad. Simroth obtained about 40 young ones at Las Caldas de Gerez, in Portugal.

Habitat. — The first living specimens I have seen were presented to me last
April by Mr. A. G. More. They had been collected on the eastern shores of
Lough Caragh, in county Kerry, the same locality where Andrews had originally
discovered the slug.

In the following May, while returning home from the dredging expedition to
the West Coast, organized by the Royal Dublin Society, I passed Lough Caragh,
and spent a portion of the night in hunting for this interesting slug, but without
success. The following morning I walked to the eastern shores of the lake, and
although I turned over hundreds of stones, I discovered nothing but Limax maximus,
L. marginatus, and Arion ater. I was about to give up the search, when I noticed a
young specimen concealed among the lichens which grow here so abundantly on
the surface of the rocks, and, after a while, I found several others similarly
exposed to the full rays of the sun, it being then about two o'clock in the afternoon.

The dark gray lichens, with the white or yellowish fructification, conceal the
slug perfectly, and there is no doubt that we have here a most striking instance
of protective colouring. Lough Caragh is situated close to the head of Dingle
Bay, in County Kerry, and, up to quite recently, it was the only spot in Ireland
where this slug had been found, but, during last autumn, Mr. Scully discovered it
about twenty-five miles further south, on the Kenmare and Glengariff road.*

I notice in Simroth's (40) proof, referred to above, that he found this species
among lichens at the foot of a granite wall in the province of Minho, in Northern
Portugal. A single specimen was collected in 1868, according to Heynemann (13),
by Lucas Von Hey den, in the province of Asturias, in Northern Spain. Two other
species, G. oliveirce and G. anguiformis, from Central and Southern Portugal, will
be described in Simroth's forthcoming Memoir (40).|

Food. — G. maculosus undoubtedly lives on lichens, as I have been able to
demonstrate by microscopic examination of the contents of the intestine.

In captivity it readily takes to other food, and thrives on dandelion leaves ;
and Heynemann (13) succeeded in keeping Irish specimens during a whole winter
on lettuce, gherkins, &c.

General Distribution.^ — Northern Portugal, and N. W. Spain.

*In May, 1891, I found this species abundantly still further South at Glengariff, county Cork,
f The question of the peculiar geographical distribution of this slug will be dealt with in a special
Memoir, which I hope to publish during the course of this year.

TRANS. ROT. DUB. SOC, N.S. VOL. IV., TART X. 4 H

554

Schahff — On the Slugs of Ireland.

The Colours of Slugs.

A good deal has been written in various Zoological works on the colours of
animals in general, and Poulton has recently published a most interesting work,
chiefly on the colours of Insects. He finds that a variety of causes influence the
production of colours, but that by far their most widespread use is to assist an
animal in escaping from enemies or in capturing its pre}7.

The view that colour is of direct physiological value to slugs has been ably
argued by Simroth in the cases of Arion ater and Limax maximus, and Eimer (6)
seems to support Leydig's view, that the darker colour of A. ater on the sea-coast
may be caused by the greater moisture of the atmosphere. However, I hope
I shall be able to show that neither of these views are altogether borne out by
facts. Cockerell (4), judging from some specimens sent to him from a mountain
in county Waterford, draws the conclusion that altitude influences the colour of
slugs, but this also, I believe, is not supported by sufficient evidence.

I think that the colours of slugs in Ireland are at all ages, as a rule, protective.
Simroth (38) agrees with this as far as the smaller species are concerned, but he
excepts Limax maximus and Arion empiricorum (= ater), because they are often
distinguished by strikingly vivid colours.

He made numerous experiments with the latter species, kept it in a hot atmo-
sphere, and offered it to various birds as food, and finally came to the conclusion
that the colour in the brick-red variety is a warning colour. The object of a so-
called warning colour, I may say, is to render the animal as conspicuous as pos-
sible, in order to enable its enemies to easily learn and remember the animals
which are to be avoided on account of any noxious properties they may possess.

Simroth (38), moreover, points out that all the very variable species of slugs,
such as Arion ater and Limax maximus, are darkly coloured both at their southern and
northern limits of range, the shores of the Mediterranean, and Scandinavia. He
supposes this to be due to a natural protection against heat and cold, i.e. he believes
that colour is of direct physiological value.

We know, however, that dark colours absorb radiant heat easily, while light
colours do so with difficulty; and it seems therefore surprising that Simroth (38)
did not take into account the fact that the white variety of A. ater in Scandinavia
is almost as common as the black [Esmark (7)]. Both on the Continent and in
Ireland the young of A. ater are brilliantly coloured during winter, and most
specimens darken at the approach of summer.

If Simroth' s theory were correct, one would expect the slugs which are destined
to resist the severe cold of a Continental winter to be coloured dark. All young
specimens, however, whether they produce black or brown adults, are light-coloured

Scharff — On the Slugs of Ireland.

555

in their youth, and the colour of the adults varies between black, brown, and red
in Germany, just as it does in Ireland, with the exception that the brick-red form
so common in Germany is absent with us.

Simroth's experiment of offering A. ater as food to various birds, and its being
refused by them, does not seem to me conclusive, as birds kept in captivity get a
regular diet, and become in time rather dainty feeders. Besides, large birds such
as gulls, are decidedly rare in Germany, and I think it much more likely that
toads or some of the insectivorous mammals do a great deal of damage among
slugs ; and it is possibly these that have a particular aversion to the bright red
slugs, owing to their more acrid slime. Their colour is certainly most conspicuous,
and on a rainy day they are often seen in hundreds in broad daylight in the
forests of Germany.

I do not believe their colour is influenced by the temperature, for we find black
and brown forms of the same species living in such a dry climate as that of Eastern
Germany and on the very humid West Coast of Ireland — in cold and bleak Norway
as well as on the parched plains of Spain and Portugal.

In this country, as I mentioned before, I have met with the uniformly black,
the brown, olive, claret, and light red varieties of A. ater, and one variety which
is black above, with yellow sides. The olive and light red forms occur only on the
West Coast, but the black and brown ones are equally common there. In boggy
ground most of those I saw were either olive or a rich burnt sienna brown. Their
colour harmonizes most perfectly with the brown of the turf and the olive-coloured
moss growing on it. I have also observed the light red in that neighbourhood, but
no natural object seemed to me to exactly resemble it.

Perhaps the wettest spot on the West Coast is the Skellig Rock, an immense
rock, entirely bare, over the greater part of which the huge Atlantic waves break,
scattering their spray completely over the highest parts. From this rock I have
the olive and black variety of A. ater. If moisture caused darkness, they would
all be black there, for a more humid place can scarcely be imagined.

Certainly, I have everywhere met with black specimens very close to the sea,
both on the West and especially on the East Coast, and that fact taken alone might
lead us to suppose that moisture had something to do with the darkness of their
colour ; but black specimens are equally common inland a long way from the sea,
whilst on cultivated ground, even if it should be quite close to the shore, we find
almost invariably the brown variety.

Another remarkable circumstance is that along the sea-shore near Dublin one
meets very frequently with the black and yellow variety, i.e. black with yellow sides
(Plate LVL, fig. 15.) A variety with white sides has been recorded from the coast
of Wales, and Simroth obtained them also from the shores of the German Ocean.

556

Scharff — On the Slugs of Ireland.

It seems clear that the sea has some connexion with this variety at any rate,
but I think its connexion is only of an indirect nature. It struck me at first that
the sides of the slugs might be more stimulated to secrete mucus than the back, as
the animals would have to crawl over grass which must be coated with depositions
of salt ; but why should they not then all be of that variety near the sea? Entirely
black ones are, in fact, rather more common.

There is another more likely explanation to account for the fact of the
bicoloured dress of the young being retained in the adult on the sea-shore.
It appeared to me that in the twilight of morning and evening the black-and-
yellow forms might have equal advantages of concealment with the black ones,
when crawling among the stones at the sea-shore, for I believe this species is just
as much preyed upon as other slugs by the innumerable birds frequenting Dublin
Bay. It is well known that the gizzard of gulls is frequently found to be filled
with slugs of all kinds, whilst Thompson (43) often found the shell of Limax
maximus and Agviolwiax in the stomach of the thrush.

The only place where I have found the claret-coloured variety was in pine
woods at Killakee and Howth, where the general colouring of the ground
resembles that of the slug, and at once suggested to me the protective character
of its colour. As regards the young winter forms of Avion ater, I have always
noticed that they choose the yellow fallen leaves, whose colour they resemble very
closely, for hiding-places, and here again it is the need of protection and not
temperature which influences their colouring.

As for the other species of slugs, we have very good examples of protective
colouring in Limax mavginatus, Amalia cavinata, Avion intevmedius, and Geomalacus
maculosus. The first, when on a tree-trunk, which is its favourite haunt, is easily
mistaken for a piece of bark ; the second resembles the ground in which it spends
almost its entire existence ; the third looks very like a little fungus just coming
out of the ground, while the last imitates the colour of the lichen among which it
lives to a remarkable degree.

In the other slugs protective colouring is perhaps not quite so apparent, but I
have no doubt that in all cases their colour is mainly influenced by the natural
selection of those best suited to escape the keen sight of their enemies.

Schaeff — On the Slugs of Ireland.

557

PAPERS AND WORKS REFERRED TO.

1 Allman, G. J., . " Description of a new Genus of pulmonary Gastropod." — Ann. & Mag.

Nat. Hist., vol. 17, 1846.

2 Baudon, Aug., . " Memoire sur les Limaciens du Departement de l'Oise." — 1871.

3 Clarke, B. J., . "On the species of Limax found in Ireland." — Ann. & Mag. Nat. Hist.,

vol. 12, 1843.

4 Cockeeell, T. D. A., " Limax arborum and the influence of altitude on colour." — Zoologist, vol.

10, 3rd ser., 1886.

5 Deapaenaud, J., . " Hist. nat. des Moll. terr. & fluv. de France." — 1805-31.

6 Eimee, G. H. T., . " Organic Evolution."— (Translated by J. T. Cunningham), 1890.

7 Esmabk, Biegithe, . "Land and Freshwater Mollusca of Norway." — Journal of Conchology,

vol. 5, 1886-88.

8 Feeussac, A.E., . " Histoire nat. des Mollusques." — 1819.

9 Foebes and Hanley, " History of British Mollusca." — 4 vols, 1853.

10 Gatn, W. A., . " A few notes on the Foods and Habits of Slugs and Snails." — Naturalist,

1889.

11 Gmelin, J. F., . " Systema nat." — 1788-90, xin ed.

12 Hanitsch, R., . " Contributions to the Anatomy and Histology of Limax agrestis — Proceed.

Soc. Liverp., vol 2, 1888.

13 Heynemann, D. F., " Uber OsamaUm^." — Malakozool. Blatter, vol. 21, 1873.

14 do. " Limax brunneus, Drp." — Malakozool. Blatter, vol. 19, 1872.

15 do. " Uber Limax variegatus, Drp." — Malakozool. Blatter, vol 7, 1861.

16 Jeffreys, J. G., . " British Conchology." — vol. 1, 1862.

17 Kew, H. W., . "Notes made in 1888 upon Avion ater and some other Slugs." — Naturalist,

1889.

18 Lawson, H., . "General Anatomy of Limax maximus." — Microsc. Journal, vol. 3, n. s.,

1863.

19 Leach, W. E., . " Synopsis of the Mollusca of Great Britain " (Proofs published in 1820).

20 Lehmann, R., . " Die lebenden Schnecken und Muscheln in Pommern." — 1873.

21 Lessona und Pollonera, " Monographia d. Limacidi italiani." — 1882.

22 Lister, M., . " Synopsis Conchyhorum, &c." — 1685.

23 Mabille, M. J., . " Le Genre Geo?nalacus en France."— Revue et Mag. de. Zoologie, vol. 19,

n. ser., 1867.

24 do. "Les Limaciens europeens." — Revue et Mag. de Zoologie, vol. 20, n. ser.

1868.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART X. 4 I

558

Scharff — On the Slugs of Ireland.

25 Malm, A. W.,

26 Moquin-Tandon, A.,

27 MOKELET, A.,

28 Muller, 0. F.,

29 Nielsson, S.,

30 Normand, N. A. J.,

31 NuNNELEY, Th.,

32 PoLLONERA, C,

33

do.

34 Reeve, L.,

35 Roebuck, W. D., .

36 Schaeff, R. F.,

37 Scott, R. H.,

38 SlMROTH, H.,

39 do.

40 do.

41 Taylor, J. W.,

42 Taylor and Roebuck,

48 Thompson, W.,

44 Westerlund, C. A.,

" Skandinaviska Land Sniglar." — 1870.

" Hist. nat. d. Moll. terr. et fluv. de France."— 1855.

" Descr. d. Moll. terr. et fluv. du Portugal." — 1845.

" Vermium terrest. et fluv. historia." — 1774.

" Hist. Moll. Sueciae terr. et fluv."— 1822.

" Descr. de six Limaces nouvelles." — 1852.

"Descr. of the Limaces found in the neighbourhood of Leeds." — Trans.
Leeds Phil, and Lit. Society, 1837.

" Specie nuove o mal conoscieute di Arion europei." — Atti d. R. Acad, di
Torino, vol. 22, 1886-87.

"Nuove contribuzioni alio studio degli Arion europei."— Atti. d. R. Acad,
di Torino, vol. 24, 1889.

" Land and Freshwater Mollusca of the British Isles." — 1863.

Numerous Notes and Papers. — Journal of Conchology, vols. 4-6, 1883-1890.

" Arion minimus (Simroth) a British Slug." — Journal of Conchology, vol. 6,
1890.

" The Variability of the Temperature in the British Isles." — Proc. Roy. Soc,
vol. 47, 1890.

" Naturgesch. d. deutsch. Nacktschnecken." — Zeitschr. f. wiss. Zoologie,
vol. 42, 1885.

" tiber bekannte und neue palaearkt. Nacktschnecken." — Jahrb. d. deutsch.

Malakoz. Gesellsch., vol. 13, 1886.
" Die Nacktschnecken d. portugies-azorisch Fauna." — Nova Acta Acad. C. L.

C. G. Nat. Cur., vol. 56, 1891 (Proof).

Numerous Papers and Notes. — See Journal of Conchology, vols. 1-6.

"Materials towards a Land and Freshwater Moll. Fauna of Ireland." —
Proceed. R. I. Acad., ser. 2, vol. 4, 1888.

"Natural History of Ireland," vol. 4, 1856.

" Fauna Europea Moll, extra marinorum," 1877-78.

EXPLANATION OF PLATE LVI.

TRANS. ROT. DOT. SOC , N.S. VOL. IV., PART X.

560

Schaeff — On the Slugs of Ireland.

EXPLANATION OF PLATE LVI.

Fig.

1. Limax maximus, L., dark variety (rather more than half-grown), from Raheny, Co. Dublin.

2. ,, ,, (not quite half- grown), from Leeson Park, Dublin.

3. ,, flavus, L. (full-grown), from Raheny, Co. Dublin.

4. ,, marginatus, Muller (full-grown), from Killakee, Co. Dublin.

5. Agriolimax agrestis, L. (full-grown), from Leeson Park, Dublin.

6. ,, ,, L., variety (full-grown) from Rathfarnham, Co, Dublin.

7. ,, laevis, Muller (twice natural size, almost full-grown), from Killakee, Co. Dublin.

8. Amalia carinata, Leach (full-grown), from Leeson Park, Dublin.

9. ,, gagates, Drap. (full-grown), from Raheny, Co. Dublin.

10. Anon ater, L., brown variety (full-grown), from Leeson Park, Dublin.

11. ,, ,, variety (half-grown), resting position, from Raheny, Co. Dublin.

12. ,, ,, variety (half-grown), not fully extended, from Howth, Co. Dublin (Redding).

13. ,, ,, variety (young), from Killakee, Co. Dublin.

14. ,, ,, brown variety (young of fig. 10), from Leeson Park, Dublin.

15. ,, ,, variety (half-grown), from Howth, Co. Dublin (Redding).

16. ,, ,, variety (half-grown), from Rathfarnham, Co. Dublin.

17. ,, subfusms, Drap. (full-grown), from Raheny, Co. Dublin.

18. ,, ,, variety (full-grown), from Howth, Co. Dublin.

19. ,, ,, variety (full-grown, sexually undeveloped), Killakee, Co. Dublin.

20. ,, hortensis, F£r., brown variety (1J times natural size, full-grown), Leeson Park, Dublin.

21. ,, bourguignati, Mabille, brown variety (1-J times natural size, full-grown), Leeson Park,

Dublin.

22. ,, intermedins, Normand (full-grown), from Raheny, Co. Dublin.

23. ,, ,, ,, variety (full-grown), resting position, from Killakee, Co. Dublin.

24. Geomalacus maculosus, Allman (full-grown), from Shore of Lough Caragh, Co. Kerry.

Trans. R.Dub. S..X. S ,Yol. IV.

Plate i.vi.

ItP.ScharfF del

LithWernei & Winter, Frankfort °'M

I

EXPLANATION OF PLATE LVIL

562

Scharff — On the Slugs of Ireland.

LETTERING ADOPTED IN ALL THE FIGUEES.

hg. . .

hermaphrodite gland.

hd. . .

. hermaphrodite duct.

ag. . .

albuminiparous gland.

OS.

ovisperm-duct.

ov.

oviduct.

sp. .

. sperm-duct.

ree. .

. . receptaculum seminis.

p. . . . penis.

rm. . . . genital retractor muscle.

fl. . . flagellum.

pat. . . . portion of sperm-duct in which sperma-

tophore is formed (Patronenstrecke) .

uv. . . . upper vestibule.

?».... lower vestibule.

ac. . . . accessory gland.

EXPLANATION OF PLATE LVII.

Fig.

25. Limax maodmus, L. (reproductive organs), very dark form, from Killakee, Co. Dublin, October,

1890.

26. ,, flavus, L. (reproductive organs), from Raheny, Co. Dublin, October, 1890.

27. ,, marginatus, Miiller (reproductive organs), from Co. Wexford, August, 1890.

28. Agriolimax agrestis, L. (reproductive organs), magnified, from Aran Islands, October, 1890.

29. ,, laevis, Miiller (reproductive organs), magnified, from Killakee, Co. Dublin, Septem-

ber, 1890.

30. Amalia carinata, Leacb (reproductive organs), magnified, from Aran Islands, October, 1890.

31. ,, gagates, Drap. (reproductive organs), from Rabeny, Co. Dublin, September, 1890.

32. Arion ater, L. (reproductive organs), black variety, from Rabeny, Co. Dublin, August, 1890.

33. ,, subfuscus, Drap. (reproductive organs), magnified, from Rabeny, Co. Dublin, September,

1890.

34. ,, hortensis, Fer. (reproductive organs), magnified, from Leeson Park, Dublin, October,

1890.

35. ,, bourgnignati, Mabille (reproductive organs), magnified, from Leeson Park, Dublin,

July, 1890.

36. intermedins, Normand (reproductive organs), magnified, from Rabeny, Co. Dublin,

September, 1890.

37. Geomalacus maculosus, Allman (reproductive organs), from Co. Kerry, May, 1890.

[ 563 ]

XI.

ON THE CAUSE OF DOUBLE LINES AND OF EQUIDISTANT SATELLITES
IN THE SPECTEA OF OASES. Bv GEOEGE JOHNSTONE STONEY,
M.A., D.Sc, F.E.S., Vice-President, Eoyal Dublin Society.

[Read March 26 and May 22, 1891.]

CONTENTS.

CHAP. PAGE

I. — Introduction, ............. 563

II. — The problem treated dynamically 569

III. — The problem treated from the standpoint of the Electro-magnetic Theory of Light, . 582

IV. — Analysis by Fourier's Theorem, .......... 585

V— Illustrations, 592

VI. — Applications, 594

Postscript, . . 607

CHAPTER I.

INTRODUCTION.

The study of the kinetic theory of gases has been pursued during the last forty
years with great success, by Clausius, Clerk Maxwell, and others, and has thrown
a flood of light upon the conditions under which the molecules of ponderable
matter subsist in the world about us. By these investigations it was discovered
that, while in solids and liquids they are so crowded together as to be unremittingly
under the influence of one another, a very different state of things prevails in
gases. In gases the moments of time during which the molecules are close enough
to act on one another are brief compared with much longer intervals which elapse
between their encounters. During these comparatively long periods of indepen-
dence each molecule is free to move in its own natural way ; and important physical
events on a large scale take place as a consequence of the motions within the
molecules which then occur.

Previously to these inquiries, Dulong and Petit had obtained by experiment the
law that the specific heat at constant volume of the more perfect gases is inversely
proportional to their specific gravity. It is further known by experiment that y,

TRANS. EOT. DUB. SOC, N.S. VOL. IV., PART XI. . 4 L

564

Stoney — Cause of Double Lines in Spectra.

the ratio of the specific heat at constant pressure to the specific heat at constant
volume, is nearly the same for all these gases, and that its value is 1*408.

From these data the kinetic theory of gases enables us to gain our first insight
as to what is going on within the molecules. These experiments, when inter-
preted by its help, show that only 0612 of the energy in the more perfect gases is
accounted for by the motions of the molecules as they dart about amongst one
another like missiles, and that the remaining 0*388 of the whole energy is the
energy of events that are going on within the molecules themselves.

We learn from electrical, thermal, and spectroscopic observations that energy
can pass from the molecules of a gas to the sether ; and we know that when a gas
warms its containing vessel or expands against pressure, external work is done by
it upon ponderable matter. Now it is very important to observe at the threshold
of our inquiry that these are the only tvays in which any energy whatever is
expended by a gas. Retarding forces of one kind or other arise in all the motions
with which we are most familiar on the earth, because the motions we are
accustomed to take notice'of are molar motions of the irrotational type, pursued
under such conditions that part of the molar energy is constantly leaking down
into subsidiary molecular activities. When, however, we get to the bottom of the
series of irrotational motions, beneath which there are none underlying, no such
degradation of energy is possible. Accordingly there is absolutely no loss of
energy in the encounters between molecules ; neither is there a trace of anything
like friction or viscosity between the different parts of a molecule to impede any
events that may be going on within it during its flight between one encounter and
the next. All its internal motions are even more free from any such interference
than are the motions of the planets, which are affected, in a minute degree, both by
meteors and by tidal actions.

Very striking information about these internal events is furnished by the
spectroscope, which reveals to us the fact that they are such as to occasion definite
undulatory changes in the surrounding sether. Each gas is in fact found to emit an
interrupted spectrum, consisting of separated lines ; of which the positions, intensi-
ties, and general appearance are characteristic of the molecules from which they
emanate. We thus become aware of the fact that each gaseous molecule, and as a
consequence each chemical atom, is an elaborate system within which highly com-
plex changes of a periodic character are perpetually taking place.

The object of the present communication is to try to cross the threshold of an
inquiry as to what these molecular events are.

In this investigation we shall have to treat of periods of time too small to be
conveniently spoken of as fractions of a second. And, fortunately, the nature of
the subject indicates the best way of dealing with them. This is by making use
of the velocity of light and other electro-magnetic waves in the open aether, which

Stoney — Cause of Double Lines in Spectra.

565

is one of the three fundamental fixed units of nature.* This standard velocity I
propose to call the Maxwell. It is a velocity of almost exactly 30 quadrants of
the earth per second, meaning by a quadrant the distance along the earth's
meridian from the equator to the pole — in other words, it is a velocity of 300
millions of metres per second. It is a velocity that pervades all nature and
establishes a natural relation, which exists everywhere, between time and length.
Accordingly lengths, such as metres, millimetres, &c., do naturally represent
definite periods of time, viz. the times occupied by light in advancing over those
distances in the open aether. But as perhaps it might be thought too great a
departure from usage to speak of metres, millimetres or tenthet-metresf of time,
I shall for our present purpose select one definite period, viz. the time that light
takes to advance the tenth part of a millimetre, and will call it the jot of time.
This little fragment of time, which is one-third of the billionth of a second, will
be found a very convenient standard in which to measure the periods which
present themselves in the study of molecular events. Thus light takes one deka-
jot to advance a millimetre ; it advances a tenthet-metre in the micro-jot, meaning
by the deka-jot, ten jots, and by the micro-jot, the millionth part of a jot. The
periodic times of the oscillations that present themselves in the spectra of gases
range from a little less than two milli-jots up to about twelve milli-jots, meaning by
the milli-jot the thousandth part of a jot. This range extends from the limit in the
ultra-violet explored by Professor Hartley to the farthest ultra-red reached by
Captain Abney. In ordinary air the flight of a molecule between its encounters
lasts on the average about 420 jots, % during which time there can, accordingly,
take place upwards of 200,000 of the swiftest and 30,000 of the slowest of the
oscillations§ spoken of above — oscillations which we must bear in mind are set up
in the surrounding aether by the events that occur in the molecules.

* See a Paper by the author in the Proceedings of the Royal Dublin Society, February 16, 1881, and in
the Phil. Mag., May, 1881, p. 384.

f A tenthet means a unit in the tenth place of decimals ; in other words it is 1/1010.

% The rate of diffusion of gases and the amount of their viscosity depend on the length of the excursion
of the molecules. Maxwell made three determinations founded on this consideration, the mean of which
is that the average length of the free path in air is a little more than seven eighthet-metres (7/108 of a
metre). See Phil. Mag. for August, 1868, p. 138, where Maxwell's results are collected. Taking
seven eighthet-metres as the length of the excursion, and 500 metres per second (the "velocity of mean
squares" in air at 18° temperature) as the speed of the molecule, the mean duration of its flights will
be 420 jots. It is probably a little more than this in air, and will vary in different gases and in the same
gas under different circumstances ; but for the purposes of this Paper a very rough approximation is suffi-
cient, and accordingly we shall use 420 jots when we want to indicate the sort of interval of time that
elapses while a molecule is on one of its journeys.

§ The word oscillation is used throughout this Paper in a generalized sense to include revolutions in an
orbit as well as vibrations in a straight line.

4 L 2

566

Stoney — Cause of Double Lines in Spectra.

The first step to connect these setliereal oscillations with motions in the mole-
cules was I believe taken by the author when, in 1870, he pointed out the
harmonic relation which exists between the lines a, /3, and S of the line spectrum
of hydrogen. These are the lines C, F, and h of the solar spectrum. Their
periodic times are inversely as the numbers 20 : 27 : 32. This gives evidence
that these three lines have their source in some one event in the molecules of
hydrogen. The next step was taken by Professor J. Emerson Reynolds and the
author working in conjunction in the laboratory of the Royal Dublin Society in
1871, when, on a careful examination of the spectrum of chlorochromic anhydride
(Cr02Cl2), it was ascertained that the sequence and intensities of a very long series
of lines in the absorption spectrum of that ruddy vapour, stand in a close relation-
ship to the sequence and intensities of the series of harmonics emitted by a violin
under definite circumstances, viz. when the string is bowed at a point nearly, but
not quite, two-fifths of its length from the bridge.* From this, and from the regu-
larity in the spacing of the lines, it appears that all the lines of this long series have
their source in some one event occurring in the molecules of the vapour. It was
also ascertained by mixing air with the vapour that this event is one which is
independent of the encounters that must then occur between molecules of the
vapour and molecules of the air. It is therefore probably a periodic event excited
and maintained by the incident light during the comparatively long periods of
flight of the molecules, which, in the experiments that were made, lasted over some
hundreds of jots, and not during the very much briefer periods when the molecules
are now and then grappling with one another in struggles, no one of which
probably can last more than some very few jots. During these brief encounters
we must presume that the motions excited by the incident light are, on the con-
trary, in part obliterated, since some of the energy which is absorbed from the
aether increases the pressure of the vapour.

The next notable event was the discovery by Dr. Huggins, that the four
hydrogen lines of the solar spectrum are part of a much longer series of lines
arranged in a conspicuous pattern, which is evidence that they are due to some
common cause. Dr. Huggins found the additional lines in the spectra of white
stars. They are absent from our Sun. This discovery was shortly followed by
a laboratory investigation, confirming the opinion suggested by the telescopic
observation, viz. that the whole series is due to hydrogen.

Then followed the very important discovery of " Banner's Law." Professor
Balmer, in 1885, showed that the law connecting three of the hydrogen lines, to
which the author had called attention in 1870, is part of a more comprehen-
sive law which includes the whole series. This comprehensive law is that

* See Phil. Mag. for July, 1871, p. 47.

Stoney — Cause of Double Lines in Spectra.

567

the oscillation-frequencies of the successive lines is given by the formula

in which k is a constant for the whole series. By putting, successively, into this
formula the whole numbers 3, 4, 5, 6, &c, for m, it furnishes values for iV, which
are the oscillation-frequencies of the successive lines. This still further establishes
the fact that these rays are caused by one event, or by one body of inter-depen-
dent events, occurring in the molecules of the gas. It can easily be seen that
the 1st, 2nd, and 4th of this series are &f£, and /fff, in accordance with the
law which I had announced in 1870.

There are many series of lines known to spectroscopists which form patterns
somewhat like that of the hydrogen series, and which we may presume are to be
referred to some one event or group of associated events occurring in the molecules
of the gas. The discovery of Balmer's law has stimulated other inquirers to
search for similar simple laws connecting the oscillation-frequencies in cases of
this kind ; and these attempts have at all events elicited useful approximate laws,
which have done science the service of making it possible for the investigator
in many important cases to pick out the members of an associated series of lines,
where the individual lines are too far separated, or too much mixed up with lines
not belonging to the series, for his eye to detect the association upon mere
inspection.* Most useful work of this kind has been carried on by Professors
Kayser and Runge in Germany and by Professor Rydberg in Sweden. It must
suffice here to give an outline of those results of Professor Rydberg's analysis
of the spectra of the monads lithium, sodium, potassium, ruthenium, and caesium,
to which a new and special meaning is imparted by the investigation in the
present Memoir.

Both Professor Rydberg and Professors Kayser and Runge findf that the
spectrum of each of these elements contains and almost altogether consists of
three series of double lines. The distribution of the pairs constituting each
series over the spectrum is such as to form a pattern somewhat like that of
the great hydrogen series to which Balmer's law applies, although no equally
simple law has been detected connecting their positions. We shall presently see

* The first work of this kind with which I am acquainted was the successful separation of one of
the hands of the spectrum of CO into two distinct series by Professor Alexander Herschel in 1883. See
Transactions H. S. Edinl., vol. xxxii., p. 454. It was carried out before the announcement of Balmer's
law, by the help of a harmonic law.

f Professor Eydherg, " Recherches sur la Constitution des Spectres d'Emission des Elements Chimiques "
{Transactions of Royal Academy of Sciences of Sweden, 1889, Bandet 23, No. 11). Professors Kayser and
Bunge, "TJber die Linienspectren der Alkalien" {Transactions of the Berlin Academy of Sciences, 1890,
St. xxviii., s. 555).

568

Stoney — Cause of Double Lines in Spectra.

that the oscillations of the lines in these spectra are not quite synchronous
with the motions in the molecules that originate them, while in hydrogen, by
reason of the extreme closeness of the double lines, they are almost exactly syn-
chronous. It will also be shown how the periodic times of the molecular motions
may be deduced from the observations.

Professor Rydberg designates by the letters P, D, and S, the three series of
pairs of lines found in the spectrum of each of the foregoing elements : P being
what he calls the principal series of pairs of lines, D a series of pairs of diffuse or
nebulous lines, and S a series of pairs of sharp lines. All the observations he has
been able to collect support the conclusion that the more refrangible line of each
pair of the series P is the stronger, while the reverse is the case in the two other
series. What this means will appear in the sequel.

Professor Rydberg is of opinion that when the lines are plotted down on a
map of oscillation-frequencies, the distance between the two lines of each pair,
which we may call A, is the same throughout the whole of each series, and even in all
the three series. It may be doubted whether the observations he has collected
are as yet sufficient to give us confidence on this point. It will doubless be
settled by the great photographs that Professor Rowland has succeeded in
obtaining with his unrivalled apparatus, and which we may hope will soon be
published. It may, however, prove to be the case ; and we shall see in the
following chapters the important meaning which would attach to it.

Finally, Professor Rydberg has ascertained that the value of A (the interval
between the lines of each pair), while it varies but little between the three series
of pairs of lines in each element, differs very much in passing from one element
to another : the pairs being closest in lithium, somewhat wider in sodium, wider
still in potassium, very wide in rubidium, and widest of all in caesium. What
this means will also be explained.

Stoney — Cause of Double Lines in Spectra.

569

CHAPTER II.

THE PROBLEM TREATED DYNAMICALLY.

The alternations of electro-magnetic stress in the aether which constitute light
form an undulation which is propagated under the same laws as the transverse
vibrations of a suitable medium. We shall in the present chapter treat the subject
under this purely dynamical hypothesis, and will in the following chapter make
those corrections which are required to convert the investigation into one under the
electro-magnetic theory of heat and light.

We shall accordingly, for the present, regard certain points in the molecules
of the gas as acting dynamically on an aether capable of receiving and transmitting
only transverse vibrations, and we have to inquire what motions of these points
within the molecules would impart to the medium the oscillations which correspond
to the observed lines in the spectrum.

Let us then fix our attention on a particular molecule M, and suppose that a
point P in it which acts on the aether has been set moving along some orbit within
the molecule by the last of the inter-molecular encounters to which M has been
subjected. We are in ignorance as to what the forces are, under the influence of
which the point P will continue its motion during the flight of the molecule ; but,
nevertheless, there is one case which admits of treatment up to a certain point ;
and on comparing the conclusions of this treatment with the simplest spectra —
those of the light monad elements — we find that the conditions which lead to it
occur in them. We shall confine our attention in the present Memoir to this case.
It presents itself whenever one or some forces acting on P are predominant over all
the others, and the treatment to be employed is the same as that with which we
are familiar in the lunar and planetary theories. In applying this method the real
course of the point P is to be arrived at by first laying down its " dominant
orbit," that is the path which P would pursue if the dominant forces were the only
ones acting on it, and by then subjecting this orbit to perturbations while P is
traversing it. These perturbations are of two kinds : — (1°) such a gradual shifting
of the position of the dominant orbit while P is revolving round it, as will bring P
at each instant to the real position which it actually does then occupy under the
influence of all the forces ; accompanied by (2°) such a gradual change of the form
of the dominant orbit as may be necessary to render it at each instant the orbit
which P would describe if the perturbating forces were then suddenly to cease
acting. If the perturbating forces be feeble these changes will be slow as well as

570

Stoney — Cause of Double Lines in Spectra.

gradual, slow in comparison with the much more rapid motion of P in the dominant
orbit, which is going on at the same time.

However complex the dominant orbit may be, it will be shown in Chapter IV.
that the motion of P in it is equivalent to the coexistence and superposition of a
number of " partials," each of which is a pendulous elliptic motion of P repre-
sented by —

x — a cos 6t, | ,j ,

y = b sin 0t,\ ^ '

a, b and 6 being constants which differ in the different partials. 6, which is the
angular velocity of the growing angle 0t, may also be called the swiftness of the elliptic
motion. It is the same as 2irm/j, where m is the frequency of the elliptic revolutions
in a jot of time. The periodic time is, of course, jjm. The value of m must lie between
80 and 500, whenever the frequency of this elliptic motion is the same as that of any
undulation in the aether which can produce a line in the parts of the spectrum that
have been explored; and as in ordinary air each molecular journey lasts on the
average about 420 jots, there is time for a vast number — say from 35,000 to
210,000 — of the revolutions of the point P represented by equations (1) to take
place during one flight of the molecule.

If the dominant orbit of P were the real orbit of P, each of its partials would
produce a single line in the spectrum. But it is not likely that the motion can go
on without its being affected by disturbing forces emanating from other parts of
the molecule, or from the aether in its neighbourhood ; and so many revolutions of
P take place during one of the flights of the molecule that there is abundant time
for the operation of these disturbing forces. Now, the investigations that have
been made into the perturbations which occur within the solar system enable us to
predict at once what kinds of effects such disturbing forces would produce. They
are (1°) an apsidal motion of the elliptic partial in its own plane ; (2°) a precessional
shifting of the line of nodes in which this plane intersects the "invariable plane";
(3°) a periodic change in the inclination of these two planes ; (4°) a periodic change
of the ellipticity of the partial. All these may be regarded as perturbations of
relatively long period, but the conditions within the molecule may be such as to
occasion (5°) disturbances of shorter period affecting any one or more of the
foregoing, and producing an effect on them somewhat like that of nutation super-
imposed upon precession. We shall accordingly proceed to inquire how each of the
foregoing perturbations would manifest itself in the spectrum.

The first problem of this inquiry only requires to be enunciated. It is —

Problem I. — How will a simple elliptic motion of P in the molecules of the
gas, such as that represented by equations (1), manifest itself in the spectrum of the

gas ?

Stoney — Cause of Double Lines in Spectra.

571

It will obviously give rise to a single line in the spectrum, whose position on a
map of oscillation-frequencies is m, and whose intensity may be represented by
a2 + b\

Problem II. — How will this simple spectrum be altered
if there is an apsidal motion of the ellipse in its own
plane ?

Draw rectangular axes of co-ordinates from the centre of
the ellipse as origin, and at an angle xjit with the axes Ox and
Oy of equation (1). Regard the axes OX and OP as fixed,
and let i//= 2irn/j. The ellipse will then travel round with an
apsidal motion such that n is the frequency of the apsidal
circuits in one jot of time. The co-ordinates of P referred to
the fixed axes are —

X=a cos 0t . cos \pt — b sin 6t . sin \pt ;
Y— a cos 0t . sin xjjt+b sin 0t . cos xpt.
equations which are equivalent to

b

In other words,

where

_ y a + b /n ... a —
Y = a-±^ sin (0 + +)t - ^ sin (0 - $)t

X — Xi + X2)
Y= Y, + Y2,
a + b

X1 = +

■g— . COS (0 + \jt)t}

and

a — b

X2 = + -— . cos(0 -\jj)t,
Z2 = -^i.sin(0-^

Fig. 1.

(2)

(3 a)

(3 b)

each of which represents a circular motion. Accordingly an elliptic motion whose
frequency is m, when affected by an apsidal perturbation whose frequency is n, is
equivalent to the motion of P resulting from the two circular motions represented
by equations (3 a) and (3 b). These circular motions are in opposite directions,

TBANS. SOY. DUB. SOC, N.S. VOL. IV., PART XI. 4 M

572

Stoney — Cause of Double Lines in Sjjectra.

their frequencies are m + n and m — n, and their radii are (a + b) / 2 and
(*-«)/ 2.

If the molecules of the gas be immersed in an aether such as we have assumed,
viz. one susceptible of transverse vibrations only, the foregoing motion will
produce two lines in the spectrum whose positions on a map of oscillation-frequen-
cies will be ot + w and m — n. Moreover, the ratio of the intensities of the two
rays propagated in any one direction from the gas through the aether will be the
ratio of (a + b)2 to (a — bf, whether we take into account the contribution from one
molecule only, or the combined effect of all the molecules.

We thus find that the double lines which are a conspicuous feature of all gaseous
spectra, and of which the spectra of the monad elements appear wholly to consist,
are accounted for by supposing that an apsidal perturbation operating during the
journeys of the molecules between their encounters, affects the dominant motion
set up in them by the encounters.

The equations hitherto given represent the motion when the apsidal motion is
in the same direction as the elliptic, and here the more refrangible line, whose
oscillation frequency is ??i + n, is the brighter. If, however, the perturbating
forces are such that the apsidal motion takes place in the opposite direction to the
revolution of P in its ellipse, we must change the sign of xjj in all the equations ;
from which it appears that it is now the less refrangible line which is the brighter.
If any of the elliptic partials should chance to be a circle, b = a, and one constituent
of the double line is of cypher intensity. Accordingly, the other alone will present
itself in the spectrum, and will have in it the position m + n when the circular
motion and the apsidal are in the same direction, and the position m — n when they
are in opposite directions. And, finally, whenever the partial of the dominant
motion represented by equations (1) is a mere vibration in a straight line instead
of a revolution in an ellipse, b, the axis minor, vanishes, and the intensities of
the spectral lines (which are always to one another in the ratio of (a + b)2 to
( a — b )2) become equal.

The following figures represent the several cases which have been considered.
All of them are met with in the actual spectra of gases.

Fig. 2 (a). — Spectrum of one of the partials of the domi- ijv

nant motion of P, viz. of a pendulous elliptic revolution of ^

P in the molecules of the gas such as that represented by

equations (1).

Fig. 2 (b). — The double line into which this resolves —

' 3

itself when the elliptic motion in the molecules is affected by | ^

an apsidal motion in the same direction as the elliptic motion. § $

In this case the more refrangible line is the stronger. See FlG 2
equations (3 «) and (3 b).

Stoney — Cause of Double Lines in Spectra.

573

Fig. 3 (a). — Simple elliptic motion as before.

Fig. 3 (b). — The double line when the apsidal motion is in the opposite
direction to the elliptic motion. Here the less refrangible line is the stronger.
This case is represented by changing the sign of \p in equations (3 «) and (3 b\

Fig. 4 (a). — Spectrum of a simple circular partial. This case is represented by
making b = a.

Fig. 4 (b). — Position to which this line is shifted when there is apsidal motion
in the same direction.

Fig. 5 (a). — Spectrum of a circular partial as before.

Fig. 5 (b). — Position to which the line is shifted when there is apsidal motion
in the opposite direction.

Fkj. 6 (a). — Spectrum of a pendulous vibration in a straight line. This case is
represented by making 5 = 0 in equations (1).

Fig. 6 (b). — The spectrum of this vibration subjected to apsidal motion. Here
the constituents of the double line are equally strong. This case is represented by
putting b — 0 in equations (3 a) and (3 b).

M

(a)

(a)

(a)

to

(b)

(&) 1

(b)

% %

+ I

Fig. 3.

+

Fig. 4.

i

Fig. 5.

Fig. 6.

Precessional Motion. — Both the revolution of P in the elliptic partial and the
apsidal rotation of the ellipse, if not subjected to further disturbance, take place in
a fixed plane ; but unless special conditions are fulfilled within the molecules the
perturbations will be such that this plane will shift its position in relation to the
"invariable plane." To represent this motion let us conceive an axis per-
pendicular to the invariable plane and passing through the centre of the ellipse.
This axis is called the invariable line. It will in general be oblique to the plane
of the ellipse, and we are to suppose the plane of the ellipse to rotate round it
while maintaining its inclination to it unchanged. Hence arises —

Pkoblem III. — What change of the spectrum will result from a precessional
rotation round the invariable line, of the plane in which the elliptic and apsidal
motions take place ?

Let us speak of the moving plane (the plane in which the elliptic and apsidal
motions take place) as plane B\ and let the invariable plane be called plane A.

4 M 2

574

Stoney — Cause of Double Lines in Spectra.

The invariable line is a fixed line perpendicular to plane A, round which plane B
is to be regarded as rotating- with a swiftness w = 2ttJc/j\ in which k is the
frequency of this motion.

The apsidal motion has already resolved the original elliptic motion into two
circular motions in plane B, viz.,

and

Xi = + s cos St,
Yi = + s sin St,

X2 = + d cos Dt, |
Y2 = - d sin Dt, )

(4a)

(U)

which are the same as equations (3 a) and (3 b) when for brevity we write s and
d for (a + b)/2 and (a — b)/2, and S and D for 0 + %ft, and $ — xjj.

Draw three fixed axes : Oz along the invariable line, Ox along the direction at
which the intersection of planes A and B arrives at the instant t, and Oy perpen-
dicular to Ox in plane A. Then if a be the angle between the planes A and B,
equations (4 a) furnish

x = s cos St (5 a)

along the intersection of planes A and B at the instant t,

y = s sin St. cos a

(5b)

along a line in plane A which is perpendicular to the intersection of A and B at the
instant t, and

z = s sin St. sin a (5 c)

along the invariable line.

Equations (5 a) and (5 are an elliptic motion of P in plane A, and when
affected by the precessional motion ut (where w = ^ttJc/J), furnish the circular
motions

X i = + s cos2 - . cos (S + co)t
Yx = + s cos2 ^ . sin (S + &>) t

(6 a)

and

X2 = + s sin

a

COS (S — 0))t

Y2 = — s sin2 - . sin (S — o))t

(6b)

equations (5 c), (6 a), and (6 represent the whole effect ; (5 c) is a rectilinear
vibration of P perpendicular to the invariable plane, and (6 a) and (6 are two

Stoney — Cause of Double Lines in Spectra.

575

circular motions of P in that plane. These will give rise to three lines in the
spectrum, of which the positions on a map of oscillation-frequencies will be

and

m + n + k, position of (6 a)
m + n — k, . . . . (6 b)
m + n , . . . -(5 c)

with intensities proportional to

2s2 cos4 ^, intensity of (6 a)^
Z

2s2sin4£, . . . .(6b)

Z

4s2 sin2 ^, cos2 ^ . (5 c)

z z

(8)

If a is small, i. e. if the plane of the elliptic motion is nearly coincident with the
invariable plane, as it probably is in the molecules of the monad elements H, Li,
Na, Rb, Cs. then the line (6 a) is strong, (5 c) is faint, and (6 b) is excessively
faint.

The foregoing investigation traces what becomes of the circular motion (4 a)
when affected by precession. A similar treatment of (4 b) is made by substituting
d for s and — D for 8. We thus obtain the following : —

Xx = + d COS2 jr COS (D — 0))t

z

Yx — —d cos2 ^ sin (D -co) t

(9 a)

a

X2 = + d sin2 - cos (D + a) t
z

Y2 = + dsin2 ^ sin (D + <o)t
z

(9 b)

and

z = — 2d sin ^ cos ^ sin Dt,

(10)

producing three lines in the spectrum in the positions

m — n — k, position of (9 a)^
m — n + k, . . . -(9 b)
m — n , . . . . (10),

(")

576

Stoney — Cause of Double Lines in Spectra.

with the intensities

a

2d2 cos4 intensity of (9 a)

2d2 sin4 -,

Id2 sin2 % cos2^, .
2 2'

.(9b)}
.(10)

(12)

of which (when a is small) the first is strong, the third faint, and the second
excessively faint.

Hence when one of the elliptic partials of the dominant motion of P is affected
by both apsidal motion and precession, we shall have an appearance in the spectrum
which may be represented diagrammatically by the following figures : where (a)
in each figure represents the spectrum of the original elliptic partial if undisturbed,
(b) what it becomes when there is apsidal motion, and (c) what it becomes when
there are both apsidal motion and precession.

All the figures are drawn to represent the state of affairs which is probably
what prevails in the monad elements, viz. apsidal and precessional motions, which
are slow in comparison with the revolution of P in the elliptic partials of its
dominant motion. In this case n and k are small in comparison with m. The
three motions may be in the same direction, or one of them in the opposite
direction to the other two. Hence arise four varieties.

Variety 1. — The elliptic, apsidal, and precessional motions in the same
direction. Here m, n, and k are all positive, and the resulting spectrum may
be represented diagrammatically by fig. 7 (c), and consists of a pair of lines with
satellites inside, the more refrangible group being the brighter.

Variety 2. — The precessional motion in the opposite direction to the other
two : m and n are positive, and k negative.

■m

(a)

(a]

(o)

(c)

+++
+ i

1 1 1
+ i

+ + +

I

+

I !

+

9»

Fig. 7.

Fig. 8.

Fig. 8 (c) represents the spectrum : a pair, of which the more refrangible is
the brighter, with satellites outside.

Stoney — Cause of Double Lines in Spectra.

577

Variety 3. — The apsidal motion opposite the other two. Therefore m is
positive, n negative, and k positive.

Fig 9 (c) represents the spectrum : a pair, with satellites outside, the less
refrangible group the brighter.

Variety 4. — The fourth variety is when both the apsidal and precessional
motions are in the opposite direction to the elliptic. Here m is positive, and n
and k are negative, and the spectrum is represented by fig. 10 (c) : a pair, with
satellites inside, the less refrangible- group the brighter.

m

m

I I I
+ I

(aj

+ + +
+ i

T 1 f

8§§

I 4

S § gj
+ + +

I +

(a)

(b)

(e)

1

3

Fig. 9.

Fig. 10.

These diagrams represent what occurs when the apsidal and precessional
perturbations are slow compared with the original orbital motion aroused by the
last encounter of the molecule with another molecule. In this case the satellites
lie, as in the diagrams, on opposite sides of their primaries, and the primaries
themselves have been displaced in opposite directions by the precessional motion.

If, however, the apsidal motion be swift, the orbital motion must be slow to
account for the close double lines that are seen in the spectrum. Such relative
swiftness of the apsidal motion seems unlikely, and accordingly I will not pursue
the supposition further than to remark that if it prevails in any gas the satellites
of both components of a double line will lie on the same side of their primaries,
i. e. either all to the right or all to the left ; and the primaries themselves will be
displaced in the same, instead of in the opposite directions, by precession.

Corollary. — If there be precessional motion of an elliptic partial without apsidal
motion, there will be three equidistant lines in its spectrum, of which the inten-
sities could be computed if a, b, a and /3 were known, ft being the angle between
the axis major of the ellipse, and the line in which the plane of the ellipse
intersects the invariable plane. For the converse problem, we can observe the
intensities of the three lines, and their interval. These will determine the value
of ft, and will furnish three equations between a, b, a and y8, but will not fully

578

Stoney — Cause of Double Lines in Spectra.

determine these latter. The middle line has the position which would be occupied
if there were no precessional motion.

The next matter to be considered is the effect of a periodic change in the
inclination of the two planes. Hence — ■

Problem IV. — In what way will the spectrum of the gas be affected if there
be a periodic change in the inclination of the plane of the ellipse to the invariable
plane ?

This problem is to be investigated exactly in the same way as Problem VI., which
is dealt with a few pages farther on. Since the angle a in equations (5 c), (6 a), and
(6 b) undergoes a periodic fluctuation, we are to write (g+ Asin yjt) instead of a in those
equations, g, h, and 77 being constants. If after making this substitution we apply
to the equations the same method of treatment as in Problem VI., we shall find
that the effect of the perturbation is to render the lines winged.

Problem V. — What effect on the spectrum will a periodic change of ellipticity
have ?

The change of ellipticity may take place in either of two ways : in one the
orbit will pass through a rectilinear form ; in the other it will pass through a
circular form.

I. — To represent a change of the first kind we must substitute for a and b
of equations (1) the following : —

(r cos et) for a,
(r sin et) for b,

where e = 2ire/j, e being the frequency of the periodic change of ellipticity.
We thus get instead of equations (1)

x = r . cos et . cos 9t,
y = r . sin et . sin 6t,

which treated as in Problem II. give

cos (9 - e) t + cos (9 + e) t ,

cos (9 - e) t - cos (9 + e) t .

These equations represent two rectilinear motions at right angles to one another,
of frequencies m + e and m — e, and of equal intensity. They, accordingly,
would give rise to a pair of equal lines in the spectrum of the gas. If there be
absidal motion also, each of these will be doubled, and two pairs of equal lines will
present themselves.

Stoney — Cause of Double Lines in Spectra. 579

II. — To represent a periodic change of ellipticity, in which the orbit passes
through a circular form, we must substitute in equations (1)

{f + p cos et) for a,

(r — p cos et) for b,
where e = 2-rre/T. We thus obtain

x — (r + p cos et) cos Ot,
y = [r — p cos et) sin 6t,

which are equivalent to

z = r cos Ot + ^ cos (0 + e) t + ^ cos {6 - e) t,

y - r sin Ot - | sin (0 + e) £ - sin (0 - e) £

This motion, if p is small, produces a at frequency m, with two equal satellites at
frequencies m + e and m — e, i. e. one on either side of the primary.

Another perturbation which may possibly present itself would consist in the
alternate contraction and dilatation of the ellipse. This is represented by the
equations

x = a . cos et . cos 6t, )

(13a)

y = b . cos et . sin 6t, )

where 6 = %Trm/j and e = 2irefj. The energy of this motion is (V + JJ)/2, if we
represent the energy of the simple elliptic motion of equations (1) by a2 + b1.

Problem VI. — What appearance in the spectrum would this perturbation
occasion : 1°, if alone ; 2°, if accompanied by an apsidal shifting of the ellipse ?
1°. Equations (13 a) are equivalent to

x = ^ . cos (6 + t) t + | cos (6 — e) t, \

b b
y = 0-.sm(d+e)t + °-sm(d-e)t. )

Hence the perturbation, when alone, occasions two equal lines of intensity
(a2 + &2)/4, at the positions m + e and m — e on a map of oscillation-frequencies.
2°. Equations (13 b) are equivalent to

X — X\ -\- #2j

y = yi+

where

- ~ cos St}

n~2
b

and

x2= - cos Vt,
ii— \ sin Dt.

y1 = 2 sin St) [ 1/2

TKANS. EOT. DUB. SOC, N.S. VOL. IV., PART XI. 4 N

580

Stoney — Cause of Double Lines in Spectra.

Let the system which is equivalent to the coexistence of motion in these two
orbits undergo an apsidal shift, the frequency of which is n. Then, proceeding
as in Prop. II., we find that each of the two orbits gives rise to a double line.
We thus get four lines at the positions and with the intensities.

Positions.
m + e + n
m — e + n
m + e — n
m — e — n

Intensities
(a + bf/8
(a + bf/8
(a - b)2/8

(a - bf/8

equal.

equal.

Hence when the perturbation is accompanied by apsidal motion there will be four
lines, which will appear in the spectrum, as in (a) or (b) of fig. 11, if e is greater
than n ; and as in (a) or (b) of fig. 12, if e is less than n.

a-

(a)

Fig. 11.

a)

Fig. 12.

It remains to consider what appearance in the spectrum would present itself if
there be a periodic oscillation in any of these perturbations, such as nutation
produces on the precessional motion of the earth. Let us — to take one instance —
suppose that the apsidal motion is affected in this way. Then —

Pjioblem VII. — If there be a periodic oscillation in the apsidal motion, what
effect will this have on the spectrum ?

To represent such an oscillation we must write

(xjjt + a sin tf) instead of xjjt
in the equations of Problem II., where

xfj = 2irn/j and £ = 2Trq[j.

Stoney — Cause of Double Lines in Spectra. 581

This substitution being made in any of the equations of Problem II., suppose in
equations (3 a), we get

Xx = cos [{9 + xjj)t + a sin £f],
Yx = sin [(6 + xP)t+a sin tf].

(14)

To see how this will operate, imagine /3 to be the value through which tjb passes
at the instant when t = r. Then for a short period of time after

sin tjk = sin /3 + cos (3 . d . £t

q

= sin /3 + cos {3 . 2n dt,

J

in which dt is to be regarded as equal to t — r for a short time after the epoch r.
Putting this into (14) we find that equations (14) during a short period furnish a line
of frequency (m + n + a cos /3 . q). By dividing j/q the periodic time of t,t, into equal
parts ; by giving to a series of /3's the values which t,t has at the commencement
of each of these equal intervals of time ; and by then supposing that the duration
of these intervals decreases while their number increases indefinitely : we find
that the total effect is the limit (when N increases indefinitely) of a band of N
lines of equal brightness, crowded towards the middle, and becoming more and
more spaced asunder towards the edge — in other words, it is a nebulous or ' diffuse '
line fading out equally* on both sides. The middle of the line has the frequency
m + n, and its wings extend from m + n + aq on the more refrangible side, to
m + n — aq on the less refrangible side.

The same appearance in the spectrum would result from a periodic oscillation
affecting either of the other perturbations ; and in Problem IV. we have found that
wings will present themselves if there is a fluctuation in the inclination of the plane
of the ellipse to the invariable plane. Accordingly, nutation makes the lines
diffuse, and a fluctuating inclination makes them winged.

* That is, equally, if the nutation is a mere pendulous one.

4 N 2

582

Stoney — Cause of Double Lines in Spectra.

CHAPTER III.

THE PKOBLEM TREATED FROM THE STANDPOINT OF THE ELECTRO-MAGNETIC

THEORY OF LIGHT.

Whether we proceed under the crude dynamical hypothesis which we have
hitherto adopted, or under the electro-magnetic theory to which we are now to
direct our attention, we must distinguish between the motions of or in the
molecules which do not affect the luminiferous aether, and certain others which
set up an undulation in it — an undulation which consists of transverse oscillations
under the dynamical hypothesis, but of alternations of electro-magnetic stresses
under the electro-magnetic theory. Among motions of the first kind, those that
do not affect the aether and are not affected by it, we are to include the following :
the progressive journeys of the molecules as they dart about between the
encounters ; the much swifter translation which carries a molecule of the gas
through the aether at the rate of 30,000 metres per second, in common with the
rest of the earth; and other motions of a like kind. There are also probably
motions in the molecule of a swiftly periodic kind that do not affect the aether, but
there are certainly some that do, and it is these that we have to investigate.

The simplest hypothesis for our purpose is to disregard the motion of the
molecule through the aether, whether that which it has in common with the earth,
or that which is peculiar to it, such as its darting about in the gas. We may
simplify the problem by disregarding these, and may treat the molecule as though
it remained at one station in the aether, undergoing internal periodic motions,
some of which are of parts that carry charges of electricity with them, and, there-
fore, act on the aether and are acted on by it ; so that periodic motions, when set
up in these parts, will cause a synchronous motion in the aether. Correspondingly,
an undulation in the aether of suitable periodic time will set these parts of
the molecule in motion, and through them, perhaps other parts of the molecule.
The distinction between the motions which do, and the motions which do not,
affect the aether, requires to be taken into account equally on the dynamical
hypothesis and on the electro-magnetic theory.

To pass from the dynamical investigation to the electro-magnetic, attention
must be given to Faraday's " Law of Electrolysis,7' which is equivalent to the
statement that in electrolysis a definite quantity of electricity, the same in all
cases, passes for each chemical bond that is ruptured. The author called attention
to this form of the Law in a communication made to the British Association in

Stoney — Cause of Double Lines in Spectra.

583

1874, and printed in the Scientific Proceedings of the Royal Dublin Society of
February, 1881, and in the Philosophical Magazine for May, 1881 (see pp. 385 and
386 of the latter). It is there shown that the amount of this very remarkable
quantity of electricity is about the twentiethet (that is, 1/1020) of the usual electro-
magnetic unit of electricity, i.e. the unit of the ohm series. This is the same as
three- el eventhets (3/10u) of the much smaller C.G.S. electrostatic unit of quantity.
A charge of this amount is associated in the chemical atom with each bond. There
may accordingly be several such charges in one chemical atom, and there appear
to be at least two in each atom. These charges, which it will be convenient to
call electrons, cannot be removed from the atom; but they become disguised when
atoms chemically unite. If an electron be lodged at the point P of the molecule,
which undergoes the motion described in the last chapter, the revolution of this
charge will cause an electro-magnetic undulation in the surrounding aether. The
only change that has to be made in our investigation to adapt it to this state
of things is to change 6t into (6t — ir/2), i.e. a mere change of phase. We, in this
way, represent the fact that it is the tangential direction and velocity of the
motion of P, not the direction and length of its radius vector, which determine the
direction and intensity of the electro-magnetic stresses in the surrounding aether.
We have further to correct for the change of phase (about one-fourth of a vibration
period) consequent upon what takes place in the immediate vicinity of the moving
charge.

Within the molecule itself the oscillation of the permanent charge probably
causes electric displacements in other parts of the molecule ; and it is possible that
it is to the reaction of these upon the oscillating charge that we are to attribute
those perturbations of which the double lines in the spectrum give evidence.
They obviously may, however, have some other source.

Beside the irremoveable electric charges which electrolysis has brought to
light, and which establish the fact that some parts of the molecule behave as
perfect non-conductors, there may presumably be temporary charges in such
other parts of the molecule as conduct. This probably happens by direct electri-
fication of the molecule when the luminous condition of the gas is produced by
the passage of an electric current through it, and it would seem that it must also
be brought about indirectly in cases of combustion, owing to the combinations and
decompositions which then occur during which some of the permanent charges
become disguised or cease to be disguised; in either case having the effect of
charging the molecule with free electricity, positive or negative.

Now, molecules whether electrified in these ways, or by the motions set up
within the molecule developing electricity as in an influence machine, must
be expected to discharge into one another when they collide, and hence will arise

584

Stoney — Came of Double Lines in Spectra.

the kind of undulation in the aether which is exhibited in Hertz's experiments.
The periodic time of this undulation is, as is known,

T=2ttx/IS. sec p,
R2S

where sin p = — — ,

S being the capacity of the molecule, / the co-efficient of self-induction in the
current, and R its resistance. It is doubtful whether S, I, and R can be such as
will bring the periodic time low enough to correspond to that of any of the
observed lines; and even if this be the case, the discharge would probably produce
only a single line in the spectrum, or a line and its harmonics. The presence of
double lines affords further evidence that the observed spectrum does not arise
from these Hertzian discharges, since they require as their cause some event
affecting the lines which operates with a sameness in all the molecules which, we
may presume, is inconsistent with the chance conditions under which discharges
between molecules would take place. But the most conclusive evidence on this
point is furnished by the reversal of the lines of incandescent gases when sur-
rounded by their own vapour at a lower temperature. This phenomenon shows
that the undulation created in the aether by one set of molecules is capable of
effacing itself by transferring back the energy of its special oscillations to
another set of the molecules that are more quiescent. This seems incompatible
with the event being a Hertzian discharge between pairs of molecules, since this
is not a process which would be reversed under the conditions supposed, while it
does exactly agree with what would appear to be inevitable if the event is the
movement of an electron in that orbit which is its natural swing.

To explain, therefore, the lines that present themselves in the spectra of
incandescent gases, it is probable that we must fall back upon the motions com-
municated by the encounters to those non-conducting parts of the molecule in
which are lodged the electrons, and upon periodic changes in the distribution of
electricity in the conducting part of the molecule consequent upon the movements
of these permanent charges. These will be synchronous, and will jointly excite
an electro-magnetic undulation in the aether with the periodic times that they
have in common.

There seems but one other point in this connexion that needs elucidation.
It may be thought that with a multitude of molecules, each oscillating within
itself, the external effect will be nil — that every molecule in which the point
P moves one way, will be counteracted by some other molecule, in which the
point P moves the opposite way. But this is to overlook the fact that, in addition

Stoney — Cause of Double Lines in Spectra.

585

to molecules acting on the aether, the aether reacts on them ; and thus each molecule
is indirectly influenced through the aether by all its neighbours, whereby the
direction and phase of its oscillations will inevitably fall into a sufficient accord-
ance with theirs.

We may therefore freely use the whole of the investigation in the last chapter
to represent what takes place under the electro -magnetic theory of light ; merely
remembering that 6t is now a quadrant in advance of where it was under the
dynamical hypothesis, so that to represent the position of the point P we must sub-
stitute (dt — 7r/2) for 6t in all the equations of Chapter II. This, in no respect,
affects any of the conclusions.

CHAPTER IV.

ANALYSIS BY FOURIER'S THEOREM.

We have hitherto treated in detail only those cases (if any such occur) in which
the original motion of the electron, set up by the encounter, is a pendulous elliptic
motion. But this degree of simplicity is not met with in any known spectrum.
The line spectrum of hydrogen is the least complex with which we are acquainted,
and the next in simplicity are the spectra of the other light monad elements,
lithium, sodium, potassium, rubidium, and caesium. In the spectrum of hydrogen
there is at all events one great series of lines (probably double lines), and in the
spectrum of each of the others three such series are known. It becomes therefore
of importance to inquire whether the entire of one of these series of lines emanates
from the motion of one of the electric charges in the molecules of the gas. The
following propositions, in conjunction with what has been done in the preceding
chapters, lay much of the foundation for following up this inquiry.

However complex the motion of a point may be, provided it takes place in a
straight line, Fourier's theorem resolves it into pendulous elements. This is enough
for the purposes of acoustics, inasmuch as the motions to be dealt with in that
science are sensibly rectilinear. But it is not sufficient when dealing with the
transmission of electro-magnetic stresses through the aether, since the alternations
of such stresses are propagated under the laws of an undulation in which the motion
of each point is restricted, not to a line but to a plane. Hence arises—

Problem A. — What theorem corresponds to Fourier's theorem when the motion
takes place along any plane curve ?

586

Stoney — Cause of Double Lines in Spectra.

(a)

Here the motion is represented by

x = Fx{t)A

where Fx and F2 may be any two functions. By Fourier's theorem, these become

% = A0 + Ai cos 0xt + A2 cos 02t + . .

+ Bx sin 0xt + B2 sin 02t + . .

y = C0 + Cx cos 0xt + C2 cos 62t + . .

+ Dx sin Qxt + A sin 92t + . .

m

where 6X = 2^9^/ T, 02=2irm2/T, &c, in which mxm2, &c, are positive integers
when Tis the periodic time (if any) of the motion, and in which mx m2, &c, are
numbers of which some at least are fractions when T is not the periodic time. If
the motion resolves itself into a finite number of terms, and if it is at the same time
one which does not repeat itself in a period however long, some of the numbers
mx m2, &c, are incommensurable. The coefficients (the A's, IPs, (7's, and -O's), are
in all cases represented by the well-known definite integrals of Fourier's theorem,
and in some cases calculable from them. It should be borne in mind that a reso-
lution effected by Fourier's theorem is unique : in every case one such resolution
exists, and only one.

We shall now proceed to prove that the four terms in these series which stand
in any one of the vertical columns of equations (b) represent a pendulous elliptic
motion ; so that equations (b) in effect resolve the original motion of equations (a),
whatever be its law, into partials, each of which is a pendulous elliptic motion.

Take any vertical column, e.g. the kth —

xk = Ak cos 6kt y

+ Bk sin 6kt,
yk = Ck cos 6kt
+ Dk sin 0J,

or, leaving the suffixes to be understood,

x — A cos 0t + B sin 0t,
y = C cos 0t + D sin 0t,

and let us try whether we can identify it with the pendulous elliptic motion

x' = a cos [0t + a), |

y' = b sin (0t + a), j
in the same plane, and of the same frequency.

Stoney — Cause of Double Lines in Spectra.

587

Let be the angle between the axes Ox and Ox'. Then the motion (d) referred
to the axes Ox and Oy becomes

X = a cos (Ot + a) cos /3 — b sin (6t + a) sin ft,

Y = a cos {6t + a) sin /3 + b sin (0^ + «) cos /3,
which when expanded becomes

X = cos 6t (a cos a cos (S — b sin a sin /3) \

— sin 6t (a sin a cos + b cos a sin

Y = cos (a cos a sin /3 + b sin a cos /3)

— sin 6t (a sin a sin /3 — & sin a cos

Now, we can determine a, b, a and /3, so as to make

a cos a cos /3 — b sin a sin /3 = + A, \
a sin a cos ft + b cos a sin /3 = — B,
a cos a sin (3 + b sin a cos /3 = + C,
a sin a sin y8 — i cos a cos ft = — D.

(/)

Hence, when a, J, a and /3, have the values so determined, the pendulous
motion represented by (d) is identical with the motion represented by (c1).
Hence the theorem corresponding to Fourier's theorem is —

Theorem A. — Any motion of a point in a plane may be regarded as the
coexistence and superposition of definite partials which are the pen-
dulous elliptic motions determined as above, one from each of the
several vertical columns of equations (b).

These elliptic partials will all be in the plane of the original motion. They
will, however, in general lie in different azimuths in that plane, and be in different
phases at any one time.*

What lends importance to this theorem is that the resolution effected by it
in our calculations is identical with that which an undulation of electro-magnetic
stresses in the open aether (as, for example, the great complex undulation which
reaches our atmosphere from the sun or a star) does actually undergo when the

* In order to characterize the kind of motion which takes place in a partial, it is sufficient to deter-
mine three constants, viz. a, I, and 6 (the axes of the ellipse and the swiftness of the motion in it). But
to determine the position of P at each instant, it is necessary to determine two more constants (3 and a
(/?, the azimuth of the ellipse in its plane, and a the position of P in it at the instant t = 0).

A continuous spectrum arises when the 0's of the partials are indefinitely close, a spectrum of lines when
they are at intervals that can he perceived.

TEANS. R05T. DUB. SOC, N.S. VOL. IV., PAET XI. 4 0

588

Stoney — Cause of Double Lines in Spectra.

undulation either advances into a dispersing medium, or suffers diffraction. In
the open aether the pendulous elliptic components travel at the same rate and keep
together, but on entering a dispersing medium they advance with different speeds
and become separated, or, if they encounter a diffraction grating they are by it
sent in different directions. It is one or other of these separations that the
spectroscope makes manifest to us.

But the motions of the electrons, the electric charges in the molecules of the
gases, which are what excite this sethereal undulation, may be motions that are not
confined to one plane. Accordingly, to study them, we must investigate —

Problem B. — What theorem corresponds to Fourier's theorem when the motion
takes place along a line of double curvature ?

Such a motion is in general represented by —

x = Fl(t);
y = F2 (t), -

These when expanded by

When referred to the rectangular axes Ox, Oy, Oz.
Fourier's theorem become —

x — A0 + Ay cos 6it + A2 cos 02t +

+ A\ sin 0xt + A' 2 sin 62t +
y = B0 + Bx cos 0xt + B2 cos 62t +

+ B\ sin 0xt + B\ sin 62t +
z = C0 + Cx cos Bxt + C2 cos 62t +

+ C\ sin Of + C2 sin 62t + ,

Let us take any vertical column from these, e. g.

xk = Ak cos 0J + A\ sin 0kt,
yk = Bk cos 6kt + B\ sin 0kt,
zk = Ck cos 0J+ C'k sin 0kt,

or, leaving the suffixes to be understood,

x = A cos 0t + A' sin 0t, '
y = B cos 0t + B' sin 0t,
z = C cos 0t + C sin 0t, )
of which (by Problem A) the first two are equivalent to the elliptic motion,

x' = u cos (0t + e),
y' = v sin {0t + e),

(a2)

(*0

ft)

Stoney — Co^se of Double Lines in Spectra. 580

in the plane of and with its axis major inclined at an angle £ to Ox: u, v,
e, and £ being determined in the same way as a, b, a and /3 in Problem A.
Thus, taking Ox', Oy', and Oz as axes, we find the motion represented by

x' = u cos (Ot + e),
y' — v sin (Ot + e),
s = C cos 0t + C sin 0*.

Let us, by equating coefficients of cos Ot and of sin Ot, determine M and N, such that

0 cos Ot + C sin 0* = M cos (« + e) + N sin (0* + e),
whereby equations (bs) become

x' — u cos (Ot + e), \
y' = v sin (0£ + e),

^ = M cos(0t + e) + N sin + e). j

Now, it is possible to identify this with the pendulous elliptic motion

x" = a cos (Ot + e + a), j
y" = b sin (Ot + e + a), J

having the same frequency, and lying in a position which can be determined.
For—

Let OX be the intersection of the plane x'y' (which is identical with xy), with
the plane x"y" ; and let (3 be the angle x"OX and y the angle x'OX. Then equa-
tions (&4) are equivalent to

X\ — u cos (Ot + e) cos y — v sin (Ot + e) sin y,

Yi = u cos (Ot + e) sin y + v sin (Ot + e) cos y,

Zl = M cos (Ot + e) + N sin (Ot + e),

the two former being in the plane xy, and Xx being along OX, the line of inter-
section.

Again, equations (cx) are equivalent to

X" = a cos (Ot + e + a) cos /3 — 5 sin (0£ + e + a) sin /3,
T" = a cos (Ot + e + a) sin /3 + 6 sin (Ot + e + a) cos fi,

in the plane x"y", X" being along OX, the line of intersection. This, if oj be the
angle at which the planes xy and x"y" are inclined to one another, is equivalent
to—

Xt =X" along the line of intersection,

Y2 = Y" cos (a, in the plane xy, and perpendicular to the line of intersection.
Z% = Y" sin oj, along fo.

4 0 2

(h)

590 Stoney — Cause of Double Lines in Spectra.

Thus the motion (c2) is equivalent to

X2 — a cos (6t+ e + a) cos /3 — b sin (0t + e + a) sin /3,
Y2 = [a cos + e + a) sin /3 + b sin (0£ + e + a) cos /3] . cos w,
^2 = [a cos + e + a) sin /3 + b sin (0^ + e + a) cos /3] . sin cu, ;

which we shall identify with the motion (65) if we can determine a, J, a, (3, y, and
<y, so as to make the coefficients of cos(dt + e) and sin (6t + e) identical in equa-
tions (b5) and (c3).

Now, the equations (<?3) are identical with

in which

X2 = cos (6t + e ). k - sin (6t + e) . p,
Y3 = [cos (0£ + e) . q — sin (6t + e) . r] . cos cd,
Z2 = [cos (6t + e) . q — sin (#/ + e) . r] . sin co,

k = a cos a cos ft — b sin a sin /3, ^
p = a sin a cos + b cos a sin /3,
= a cos a sin ft + b sin a cos y3,
r = « sin a sin /3 — b cos a cos /3.

Identifying the coefficients in (#5) and (c4) we find that the equations to be satisfied
are —

k — u cos y, (e^

j» = sin y, (e2)

cos co = u sin y, (<?3)

r cos <u = — v cos y, (e4)

sin o> = J/, (g5)

r sin co = — N. (e6)

From (e3) and (e5), we find that

tan co =

M

Similarly, from (e4) and (ee) we find that

Equating these, we find that

tan co =

tan y =

u sm y
v cos y'

(/i)

(/0

which determines y. Having found y, equations C^x) and (e2) determine k and p,
and equation (/i) determines co ; and having found y and w, either equations (e4)

Stoney — Cause of Double Lines in Spectra.

591

and (e5) or equations (e5) and (e6) will determine q and r, and the determinations
in whichever way made are identical. Hence k, p, q, and r become known, and
equations (d) enable us from them to determine a, b, a and /3.

Hence, the form (a, b), the phase (a + e), and the position y, w), of the
elliptic motion, can be determined in terms of u, v, 31, N, and e, of equations (&4) ;
and thus, through them, the elliptic motion is completely determined in terms of
the coefficients A, A', B, B', C, C and 6, of one of the vertical columns of equa-
tions (a2). We accordingly arrive at the conclusion that —

Theorem B. — Any motion of a point in space may be regarded as the
coexistence and superposition of one definite set of partials which are
the pendulous elliptic motions determined as above from the several
vertical columns of equations (a2).

These partials will, in general, lie in different planes, and be in different phases.
The periodic time of each will be the periodic time of that vertical column of equa-
tions (a2) from which it is derived. Seven constants are associated with each
partial — of these, a, b, and 0 give the ellipse and the swiftness of motion in it, y and
oi give the position of its plane, /3 gives its position in that plane, and finally (a 4- e)
gives the position in the ellipse at which P was at the instant t = 0.

Before proceeding further it may be well to refer again to an objection that
is likely to be felt. It may at first sight seem very improbable that within a
molecule there can be parts of it moving so freely as to describe definite orbits that
suffer steady perturbation. But we must remember, as was pointed out on p. 564,
that in dealing with the internal motions of molecules we have reached a stage
where there is no longer any degradation of motions such as that effected by
friction or viscosity — in fact where the motions, whatever they are that occur in a
molecule during its flights, are performed without loss of energy other than that
communicated to the aether — with no loss whatever arising from the dynamical relations
of the parts of the molecule to one another.

The onty alternative hypothesis is that the molecules are rigid. Here we
might have a rotation, and if the three principal moments of gyration were unequal
we should have the instantaneous axis describing an elliptic cone, and so supplying
the condition for double lines. But, nevertheless, the hypothesis is inadmissible,
as it would necessitate a constancy in the rotation which is inconsistent with the
varying brightness of the spectrum at different temperatures, and which indeed
independently of this could not survive the collisions that are going on, as is
evident from dynamical considerations. We may therefore adhere with confidence
to the hypothesis made in this Memoir, that there are relative motions going on
within the molecules which are unimpeded except by the aether.

592

Stoney — Cause of Double Lines in Spectra.

CHAPTER V.

ILLUSTRATIONS.

When a chord is played by an orchestra, a very complicated undulation spreads
around it through the air. This involved motion admits of two successive resolu-
tions into simpler elements, first by regarding it as the coexistence and super-
position of undulations emanating from the several instruments each of which
by itself would produce the effect on the ear of a musical note ; and next by
the further resolution of the note emitted by each separate instrument into its
pendulous elements whose coexistence is what gives to the tone of that instrument
its special quality. So long as the undulation advances through the air, these
elements are not separated from one another ; but their presence is indicated
analytically in the fullest detail by Fourier's theorem, and the ear of a highly
trained musician is a means by which they may in practice be partially distinguished.
Such a person can completely effect the first resolution, i.e. can distinguish each
separate note, and can imperfectly effect the second resolution, i.e. he can distinguish
the qualities or clangs of these separate notes ; but his ear is powerless to complete
the resolution by distinguishing the individual partials or pendulous elements,
whose presence is what determines the distinctive sound of each instrument. Now
that which the ear does imperfectly in the case of sound the spectroscope does
fully in the case of light.

In this comparison between light and sound, each molecule of the gas cor-
responds to the entire orchestra ; and the orbits described within it by its several
electrons are what correspond to the vibrations of the sounding-boards, columns of
air, &c, of the instruments, these being the parts of the orchestra which act
directly on the surrounding medium. The undulation in the luminiferous aether
which emanates from a molecule of the gas corresponds to the waves that fill the
atmosphere when a chord is being played by the instruments of the orchestra.
That we can resolve this into the notes emitted by the individual instruments cor-
responds to our being able in some cases to divide the lines of the spectrum of a
gas into groups, each of which may be attributed to the motion of one of its
electrons. The patterns which we may observe in these groups of lines correspond
to the clangs or qualities of the notes of the orchestra ; and, finally, the individual
lines themselves supply us directly with the intensities and periodic times of the
individual partials which are the ultimate elements into which Fourier's theorem
resolves every undulation of the aether, however complex.

Stoney — Cause of Double Lines in Spectra.

593

The "partials" or ultimate elements into which a sound-wave in air can be
resolved take the very simple form —

x = a cos Qt.

They are pendulous vibrations in a straight line, and we may regard each of
them as fully characterized if we can ascertain the values of its a and 6. These
are furnished by the intensity and pitch of the corresponding simple sound, which
can be determined experimentally by the use of resonators.

This simplest form is also the form of the ultimate elements into which the
motions going on in the instruments of the orchestra are to be revolved. They are
all partials of the form x = a cos 6t, fully characterized when we can determine
a and 6.

If, however, we want to make out what is the actual motion that is going on, it
is not sufficient to characterize its individual partials correctly, it is also necessary
to be able to combine them : and to do this we must know the phases in which
they all have been at some one instant of time. Now it is still a moot point
whether we can elicit any information about the phases from an analysis of the
resultant sound : we certainly cannot elicit enough of information in this way. To
acquire it we must have recourse to a study of the instruments from which the
sound has come, and, unfortunately, in the case of light we are in the predicament
of not being able to do what corresponds to this.

Neither are the partials of the sethereal undulation so simple as in the case of
sound. Each sethereal partial is a pendulous elliptic revolution in the plane of the
wave, of the form

x = a cos 6t, y = b sin 6t,

or rather it is some change of varying electro- magnetic stresses that follows this
law. We may, however, for clearness and convenience, continue to speak of it as a
motion in the plane of the wave, it being understood that what is meant is some
change in the aether which follows the same law as the motion. Now to characterize
the above partial of such a motion, three quantities are required, a, b, and 9 ; and
what we can observe by separately examining its spectral line is not enough to
determine three quantities. The position of the line on the map of oscillation-
frequencies tells us the value of 6, its intensity determines a2 + b2, and this is all
that is given us by the examination of a single line. We have enough, however,
if we independently know of some other equation between a and b. Thus from
Chap. II. we know that b = + a for one of the two constituents of a double line,
and that b = — a for the other. In the case of double lines, therefore, the two cor-
responding partials of the motion in the aether are completely determined. Again, if
satellites arise in any of the ways pointed out in Chap. II., when not due to cir-
cular, they are due to rectilinear vibrations. Here again, since b = o, the partial

594

Stoney — Cause of Double Lines in Spectra.

may bo completely determined by observation of the line. Now it is probable that
all the lines of the spectra of H, Li, Na, K, Rb, and Cs fall into one or other of these
categories, and if this is so, all the partials of the cethereal undulation causing these
spectra can be determined by observations with the spectroscope.

We have next to consider the motions going on in one of the molecules of the
gas. These correspond to the motions going on in an orchestra ; and of them the
only ones to which we have a direct clue are the motions of the electrons them-
selves, since we can only work back from the effect on the aether and these are
the only motions in the molecules that act directly on tho aether. They correspond
to the motions of the sounding-boards of the stringed instruments and the columns
of air in the wind instruments of the orchestra, as these are what act directly on
the surrounding atmosphere.

Here, again (see last chapter), the motion of the electron may be resolved into
elliptic partials of the form,

x = a cos 6t, y = b sin 6t ;

but as the electron is not necessarily confined to one plane, we must remember that
its path may be a curve of double curvature, in which case the elliptic partials
will lie in different planes, see p. 591.

CHAPTER VI.

APPLICATIONS.

We may, however, best form a judgment as to how far observations with the
spectroscope will carry us by studying some one spectrum. The spectrum of any
of the above-mentioned monads would do, but amongst them that of sodium seems
the best adapted for our purpose.

Professor Rydberg has collected and analyzed the principal observations on
this spectrum, and I follow the selection from amongst them which he made,
adding to them the determinations since made by Professors Kayser and Runge.
Thirty-five lines, thirteen double lines and nine others, had been observed.* Pro-
fessor Rydberg conjectures that they are all, except one satellite, double. In this
connexion it should be noted that, in accordance with the analysis given above on
page 572, even where there is the apsidal motion which produces double lines, one
of a pair may be of cypher intensity, and, accordingly, the line as it appears in

* Two others more refrangible, and belonging to series P, have since been announced by Professors
Kayser and Runge.

Stoney — Cause of Double Lines in Spectra.

595

the spectrum may be single. This will happen whenever the corresponding
pendulous component of the dominant motion of the electron is circular.

Of the thirty-five known lines, Professor Bydberg arranges thirty-two in the three
following series,* and the three remaining lines he supposes to be satellites of the
third and fourth terms of series D. We must, however, here be on our guard
against lines that are intruders, and owe their presence to impurities in the sodium.
We should also bear in mind that they or some of them may be sodium lines which
are members of a series, if such exists, the rest of which lies beyond the part of the
spectrum that has been explored.

Using the language of acoustics, we may regard the whole spectrum as an optic
chord which is being played by the molecules of sodium. Each of Eydberg's
series will then be one of the notes of this chord, and the individual lines will be
the partials of these notes. The three optic notes are —

Series P (the principal series) of lines that form a definite pattern, and in each
pair of which the more refrangible line is the stronger.

Series P.

Term of Series
according to

Recorded character of lines.

Kayser and Runge's

Measures
(on Rowland's Scale).

55
<]

i

Earlier determinations of A

0

(on Angstrom's Scale).

Rydberg.

a =rl/t

K = fl . N

ll

<

First,

j

Easily reversed,

5896-16
5890-19

169-602
169-774

M

5895-13 ) 0

> Angstrom.
5889-12 )

Second,

Easily reversed, . . . . j

3303-07
3302-47

302-749
302-804

| -085 |

3301- 2 )

> Cornu.
3300- 8 )

Third,

Easily reversed, . .

2852-91

350-519

2853- 3 Liveing and Dewar.

Fourth,

Easily reversed,

2680-46

373-070

2679- 0 Liveing and Dewar.

Fifth,

Easily reversed,

2593-98

385-508

2593- 3 Liveing and Dewar.

Sixth,

Easily reversed,

2543-85

393-105

Kayser and Eunge.

Seventh,

Easily reversed,

2512-23

398-053

Kayser and Runge.

* Professors Kayser and Runge, using a different formula from Professor Eydberg's, distribute them
into tbe same three series.

TB.ANS. HOT, DUB. SOC, N.S. VOL. IV., PART XI. 4 P

596

Stoney — Cause of Double Lines in Spectra.

Series D of lines that are diffuse, that form a definite pattern when plotted down
on a map, and in each pair of which the less refrangible line is the stronger.

Series D.

Term of Series
according to
Rydberg.

Recorded character of lines.

Kayser and Runge's

Measures
(on Rowland's Scale).

<

i

Earlier determinations of K
(on Angstrom's Scale).

A = T/^

K = LI . N

II

Second,

j

(8200-3)
(8188-3)

121- 947

122- 126

1 "179

8199 j

> Abney.

Third,

Nebulous towards the red, . . <

5688-26
6682-90

175-801
175-967

1 '166

5687-3 )

} Thalen.

JDol 0 1

Satellites(P) . .

Nebulous towards the violet, <

5675-92
5670-40

176-183
176-354

•171

5673-6 \

[ Liveing and Dewar.

OODo (D /

Fourth term \
and >
otiteiiixe \: j j

Nebulous towards the red, . . <

4983-53
4979-30

200-661
200-831

■170

4983 )

4982 > Liveing and Dewar.

Fifth,

Nebulous towards the red, . . <

4669. 4
4665- 2

214-160
214-353

1 '193 1

4667-5 )

> Liveing and Dewar.
4663-7 )

Sixth,

Very nebulous, . . . . J

4500- 0
4494- 3

222-222
222-504

J -282 I

4496-4 \

\ Liveing and Dewar.
4494-5 )

Seventh,

Nebulous, . . . . . . <

(4393- 7)
(4390- 7)

227-599
227-754

•155 J

4393 )

J Liveing and Dewar.
4390 )

Eighth,

Part of a band, . . . .

(4325- 7)

231-177

4325 Liveing and Dewar.

Series S of lines that are sharp, that form a definite pattern, and in each pair of
which the less refrangible line is the stronger —

Stoney — Cause of Double Lines in Spectra. 597

Series S.

Term of Series
according to

Recorded character of lines.

Kayser and Runge's

Measures
(on Rowland's Scale).

55
<

Earlier determinations of A.
(on Angstrom's Scale).

Rydberg.

A = Tjn

K = /U.N

ll

<

Second,

(11421- 9)

87-550

11420 Becquerel.

Third,

Slightly nebulous towards the red j

6161-15
6154-62

162-307
162-480

6160-2 )

} Thalen.
6154-4 )

Fourth,

Slightly nebulous on both sides, j

5153-72
5149-19

194-035
194-205

5155-0 \

> Thalen.
5152-7 )

Fifth,

Slightly nebulous on both sides, j

4752-19
4748-36

210-429
210-599

l"7ol

4751-4 )

\ Liveing and Dewar.
4747-5 )

Sixth,

O 1 •Til 11 1 j 1 * 1 1

Slightly nebulous on both sides, j

4546-03
4542-75

219- 972

220- 131

i ,«i

! 1,9 1

4543-6 )

\ Liveing and Dewar.
4540-7 )

Seventh,

Sharp, . . . . . . j

(4423-7)
(4420-2)

226-055
226-234

4423-0 j

> Liveing and Dewar.
4419-5 )

Eighth,

Part of a band,

(4343-7)

230-219

4343 Liveing and Dewar.

In these Tables —

\ (the wave-length in air, measured in tenthet-metres) is given by observa-
tion.

k (the " inverse wave-length," the number of waves in the tenth of a milli-
metre in air) = \0e/\.

T (the periodic time of the oscillation measured in micro- jots) = ^ X.

being the index of refraction of air for that wave-length.

N (the " oscillation-frequency," i.e. the number of oscillations in each jot of
time) = x/fi.

AN (the interval between the constituents of a double line on a map of
oscillation frequencies) = A/c//u.

4 P 2

598

Stoney — Cause of Double Lines in Spectra.

The numbers in brackets are determinations not made by Kayser and Runge.
They are the earlier determinations reduced to Rowland's scale.

An accurate determination of the values of ^ throughout the spectrum is very
much wanted. However, so far as AN is concerned, ^ differs so little from unity
that AN need not be distinguished from A/c, until much more refined observations
are made than those hitherto recorded.

These three optic notes P, D, and S, with possibly a fourth one (the existence
of which there is some slender ground to suspect), make up the optic chord emitted
by the molecules of sodium. Nor is the case of sodium an isolated one : all the
other light monad elements, Li, K, Rb, Cs, emit optic chords of essentially the same
character, consisting of three notes P, D, and S, closely resembling those of sodium
in many important respects.

The optical clang of these notes — the relation in which their partials stand to
one another — may be roughly exhibited to the eye by plotting them down on
separate maps of oscillation-frequencies, when the pattern which the lines make
becomes conspicuous. The scale of the diagram is too small to show that any of
the lines are double. In fact, most of them are so (see foregoing Tables).

80 O OOOO

O o OOOO

© o 00000

400 300 200 100

K = flN

1

Series P.

Series D.

Series S.

Ultra-violet. Visible part of the spectrum. Ultra-red.

The spectrum as seen has the much more disorderly appearance which would result
from plotting them all down on one map.

Professor Rydberg is of opinion that the value of A/c (the interval between the
constituents of each pair) is the same in all the pairs of sodium, and that the
recorded discrepancies are due to the roughness of the observations. This is a
matter that careful observations will decide. Meanwhile we are concerned with
studying the inferences that can be drawn; and in order to do this it will be
convenient to take series S first.

\ = T//*

Stoney — Cause of Double Lines in Spectra.

599

Series S.

S (a). If, as appears to be the case, Series S consists of double lines none of
which has a satellite midway between its components, it follows from our investi-
gation that —

The path of the electron, from which this series arises, is a plane curve.

S {b). If further, as Professor Rydberg supposes, the A/c's (or rather the AiV's,
which are practically undistinguishable from the Ak's) are identical in the several
double lines of the series, it will follow that —

The dominant orbit of the electron (as started by the last encounter
with another molecule) is affected during the subsequent flight of the mole-
cule by an apsidal perturbation, which carries the orbit as a whole round
in its own plane, without altering its form.

S (c). If. moreover, as Professor Rydberg concludes from the observations,
the less refrangible line of each of the pairs is the brighter, it will follow that —

The elliptic partials of which the undisturbed orbit consists are all de-
scribed in the same direction, and that this direction is the reverse of that
in which the apsidal motion takes place.

S (d). No satellites such as those described in Problem III., p. 576 have been re-
corded in connexion with the lines of this series. If further observation establishes
the fact that none such exist, it will follow that —

The perturbating forces do not occasion any precession.

S (e). Professor Rydberg concludes from the observations that A«r for this
series = "146. The correction which should be applied to this to allow for the
dispersion of the air is inappreciable, so that we may take 0*146 as the value of
AN, the difference of the oscillation-frequencies of the two rays. Now, by Problem
II., n (the frequency of apsidal circuits) = \ AN. It is therefore 0*073 or nearly
1/14. If this determination is correct it follows that —

One apsidal circuit lasts during 14 jots of time; so that about 30 of these
will on the average be described during each flight of the molecule
between its encounters.

S (/). Meanwhile a vast number of revolutions in the elliptic orbits of the
partials will have taken place, ranging from 1226 during each of the 30 apsidal
circuits in the case of the least refrangible of the observed double lines of the

600 Stoney — Cause of Double Lines in Spectra.

series, to 3223 revolutions during each apsidal circuit in the most refrangible of
the observed pairs. Exact information on these points will be obtainable if ade-
quate observations can be made.

8 (g). The actual form of the elliptic orbit of each of the partials can be ascer-
tained from observations on the brightness of the lines. See below, p. 603.

This is a considerable body of information about the motion in the molecules
which causes series S, all of which is within our reach if adequate observations
can be made.

Series D.

When we turn to the series of diffuse lines, we find that it resembles series S in
most respects, with, however, three notable points of difference : — the lines are
brighter in series D than in series 8 ; they are diffuse instead of sharp; and some
satellites (or supposed satellites) are present.

That the lines are brighter betokens that the partials of the primary motion of
the D electron are motions in larger ellipses than those of the 8 electron ; and how
much larger may be ascertained so soon as measures of their relative brightnesses
shall have been made. As to satellites, three supposed satellites are recorded, one
apparently midway between the lines of that which Professor Rydberg regards as
the fourth pair of the series. If, when adequate observations are made, it is found
to be really midway between them, it will indicate that the corresponding partial
lies in a plane which is inclined to the plane of the apsidal motion at an angle which
can be determined so soon as the relative brightnesses of the three lines (the double
line and its satellite) shall have been measured. See Corollary,* p. 577.

No similarly placed satellites are recorded of the other terms of series D. If
upon an adequate scrutiny it is found that there are none such, it will indicate that
all the partials of the primary motion, except one, lie in the plane of the apsidal
motion. But as there is one which does not lie in that plane, the primary motion
of electron D must be a curve of double curvature.

Professor Rydberg thinks the observations warrant the conclusion that Ak is
the same in all the pairs of this series, and even that it is the same in all the three
series. If it has the same value in all the terms of series D, it will indicate that
the primary motion of electron D is in an orbit of double curvature which, without
changing its form, shifts round in a definite plane (which is the plane of all but one
of its partials) with an apsidal motion of which the frequency is A/c / 2.

* "What it is here convenient to regard as apsidal motion in a plane inclined to the plane of the partial,
is identical with that which in the Corollary (p. 577) is perhaps more accurately described as precessional
motion unaccompanied by apsidal motion.

Stoney — Cause of Double Lines in Spectra.

601

Finally the lines are diffuse. If it be further the case that they are similarly
diffuse, and that the thicknesses of the lines (when plotted down on a map of
oscillation-frequencies) are everywhere the same, we must attribute the diffuseness
to a common cause, which may be that the apsidal motion of the dominant orbit
of electron D is not a shifting of the orbit with uniform angular motion, as it is in
the case of electron S, but that there is a subsidiary perturbation of this motion
which bears to it the same relation that nutation does to precession in the rotation
of the earth. The oscillation-frequency of this nutation can be determined by
measuring the thickness of the lines. See p. 581. As the lines are found to be more
winged on their less refrangible side, the subsidiary perturbation that causes them
is more complex than a mere pendulous oscillation ; but until all that observation
can tell us is known it would be useless to search further for the cause.

I have not taken into account the two lines which are close to the third term of
series Z>, and which Professor Rydberg regards as satellites to that term. Professors
Kayser and Runge conjecture that they do not belong to any of the series P, D
and S, but that they are the only visible term of a fourth series of which the rest
lies beyond the parts of the spectrum that have been explored ; and they point out
in support of their view that the constituents of this pair are winged towards the
violet, while all the lines that are known to belong to series D are winged towards
the red. Their positions forbid our attributing them to the circumstances which
may produce quadruple lines sketched out in Problems V. and VI. However,
we shall be in a better position to deal with this group of four lines when more is
known of their distances and intensities.

Series P.

The remaining lines of sodium that have been observed, including the great
yellow double line, form another natural group which Professor Rydberg
calls the principal series. All but one of the terms of this series are of high
refrangibility. Some of them are known to be double lines ; in others only a
single line is (as yet) recorded. If they turn out to be single, they probably arise
from partials that are circular. The recorded observations upon the spectra of
sodium, potassium, and rubidium show that Ak is not the same in all the pairs of
series P, which indicates that the perturbating forces acting on Electron P
are such as to induce different rates of apsidal shift upon the several partials of
its dominant motion. Accordingly, the dominant orbit undergoes a change of form
as well as of size and position during the flight of the molecule. The double lines
of series P are characterized by having their more refrangible constituent the
brighter, in which respect they differ from the double lines of series D and S. It

602

Stoney — Cause of Double Linen in Spectra.

follows that the apsidal motion in series P is in the same direction as the revolutions
in the partials, whereas in series D and S it is in the opposite direction. In most
other respects the analysis of this series is much the same as that which has been
applied to series S ; and any further separate treatment of series P as a whole is
premature till more accurate observations shall have been made.

But the great yellow sodium line which is the first term of the series, and which
corresponds to the Frauenhofer line D in the solar spectrum, has been more care-
fully observed than any other of the sodium lines, and is on this account the best
in which to illustrate the extent of the information which can be elicited from
observations on a double line in the spectrum.

For this investigation it is best to use the wavelengths-in-air of Professor Row-
land's great map of the Solar Spectrum issued in 1888. Reading from it, the
wavelengths-in-air of the two D (sodium) lines are —

X1 = 5896*15 tenthet- metres,
X2 = 5890-20 tenthet- metres.

Taking the reciprocals of these, we find the number of waves in the tenth of a
millimetre in air to be

Kl= 169-602,
Kl = 169-773;

multiplying the former, and dividing the latter, by 1*000295 (Ketteler's value for fx,
the index of refraction of air, for this part of the spectrum, Phil. Mag., Nov., 1866,
p. 341), we find for the wavelength in vacuo, which is the same as the periodic
time expressed in micro- jots —

T^fiXi = 5897*89 micro- jots,

T2 = fj.\2 = 5891*95 micro-jots ;

and for the number of waves in the tenth of a mm. in vacuo, which is the same as
the frequency of the undulation of the aether in each jot of time —

iVj = Kj/ju, = 169*552 in each jot,

N2 = K2/fi = 169*723 in each jot.

Now by Problem II., p. 572, N1 = m — n, N2 = m + n, where m and n are respectively
the frequencies of the revolution of the electron in its ellipse, and of a complete
circuit of the apsidal motion. Hence —

m (the number of elliptic revolutions in each jot) = ~^2 1" ^ = 169*637,
n (the number of apsidal circuits in each jot) = ^2 ^ == -0855.

Stoney — Cause of Double Lines in Spectra.

603

From these values it appears that the partial which causes the great yellow
double line of sodium is one in which the electron makes m/n = 1984 elliptic
revolutions, while the apsidal motion carries the ellipse once round. An apsidal cir-
cuit is completed in 1/n = 11 '7 jots. And there is time for about 420 n = 36 of these
complete apsidal circuits to take place during the average flight of a molecule be-
tween two consecutive encounters, assuming this journey to occupy about 420 jots.

The more refrangible of the two lines is known to be the brighter ; and I hope
soon to have the means of making a good determination of the ratio of their
brightnesses. Meanwhile the best estimate I can at present make gives this ratio
as lying somewhere between 3 : 2 and 4:3. Now these numbers are nearly in the
ratios of 36 : 25 and 49 : 36. We may assume, therefore, that (a + bf : (a — bf lies
somewhere between these ratios, and that, therefore, a : b lies somewhere between
11:1 and 13:1. Accordingly the partial in this case is a long-shaped ellipse, in
form somewhere between the two ellij)ses delineated in the figure. Round

Fig. 13.

this ellipse the electron travels 1984 times while the ellipse shifts gradually once
round in the same direction, and something like 36 of these slow apsidal circuits
are performed during each rectilinear flight of the molecule. These are the
events that occur in the partial which gives rise to the great yellow double line of
sodium ; and an equal amount of information may be obtained in the case of every other
double line that can be observed with the requisite accuracy.

It has been mentioned that the three series P, D, and S appear in the spectra
of all the light monad elements, except hydrogen, viz. of Li, Na, K, Rb, and Cs;
and it may be added that they are found in positions in the spectrum of pro-
gressively lower refrangibility in the order in which the elements are named,
i.e. in the order of their atomic weights. Another remark that should be made is,
that when we compare the spectra of these elements with one another the value
of A/c is found to increase with the atomic weight, showing that the apsidal motion
is swifter, and, therefore, that the perturbating force is stronger in the more massive
molecules. A series, very much like one of the foregoing, is found in the spectrum
of hydrogen, but it is in a situation of too low refrangibility to be any one of
these in the case of an element with such low atomic weight.*

* One is almost tempted to conjecture that all the light monads, including hydrogen, have similar
spectra, and that there are four series in each, H, P, D, and 8, of which H appears in the spectrum of

TRANS. EOT. DT7B. SOC, N.S. TOL. IV., PAST. XI. 4 Q

604

Stoney — Cause of Double Lines in Spectra.

The spectra of the heavier monads, Cu, Ag, and Au, have not been sufficiently
explored to be used here for purposes of illustration. They appear to consist of
double lines, one of the constituents of which is often faint, and has been recorded
as a satellite, indicating that the elliptic partials in these cases are open ellipses
approaching in form to the circle. In the spectra of elements of higher atomicity
triple lines present themselves, the discussion of which lies beyond the scope of
the present Paper.*

It appears from the investigation developed in this Paper, that when the lines
of a spectrum are double, it is possible to extract from the observations a great
deal of information as to each of the elliptic motions which, when put together,
make up the actual motion of the electron. It remains to consider whether it is
possible to combine them, and so to ascertain what the actual motion is.

Where, as in the case of hydrogen, such a law as Balmer's can be empirically
obtained, there can be no doubt that all the lines (or pairs of lines) connected by
so explicit a law, arise from the successive partials of the actual motion of one
electron. Neither can there be a reasonable doubt where, by graphical processes
or by using approximate empirical formulas like that of Professors Kayser and
Runge or that of Professor Rydberg, it is found possible to pick out the lines
belonging to a natural series, especially when, as generally happens, the lines
so indicated are found by observation to have characteristics in common. The
whole of such a series we may with confidence refer to the motion of one of the
electrons in the molecules of the gas. In both these cases observations with the
spectroscope will give much information about the several partials of the motion
of the electron.

But all this information falls short of being sufficient to enable us to give

hydrogen, but has not yet been detected in the spectra of the others because of its very low refrangibility
in them, and of which P, D, and S lie so far in the ultra-violet in the spectrum of hydrogen that they have
not yet been observed.

* In the present Memoir we are dealing only with perturbating forces that are feeble. If the pertur-
bating forces were comparable with the forces which produce the orbit which we select as the dominant
orbit, triple lines might arise. For example, a motion represented by

x - a cos (t,t + a) . cos (rjt + /3) . cos 6t,

in which £, rj and 0 have nearly equal values, would produce a triple line in association with a single line

far separated from it.

It thus appears that even a vibration in a straight line may be such as will produce triple lines. And,
of course, more complex motions can generate them under fewer restrictions. But in all cases, if (as is
always possible) the motion be resolved into motion in a simpler ' dominant ' orbit affected by pertur-
bations, the perturbations, or some of them, must be of large amount, i. e. must have periodic times which
are comparable with that of the motion in the ' dominant ' orbit. In fact, slow perturbations give rise to
close equidistant lines, so that triple lines, other than those that are equally spaced, can arise only in
cases where the orbit corresponding to our dominant orbit is not predominant over some of its perturbations.

Stoney — Cause of Double Lines in Spectra.

605

a full symbolical representation of the resultant motion. If em represents the
elliptic partial whose frequency is m, then the resultant motion may be concisely
represented by the symbolical equation

Resultant motion = eml =j= em2 =f em3 4= &c.,

where the symbol =j= signifies " superposed upon." Now, of these several elliptic
components, we can obtain from the observations full details, except unfortunately
in at least two particulars. There is nothing in the spectrum which can reveal
to us the phases in which either they, or the apsidal motions by which they are
affected, are at any one instant of time : and these phases are essential to the com-
pleteness of the symbolical equation, which when written out in full would appear
as follows : —

The position of the electron at the instant t

is identical with

the position of the point P at that instant in the pendulous elliptic
component whose frequency is mi

superposed upon

its position at that instant in the pendulous elliptic component whose
frequency is m2

superposed upon,
&c, &c, &c.

There are under the most favourable conditions at all events two unknown
constants in each term of the above symbolical equation, and under unfavour-
able conditions the number of unknown constants may be five — constants to the
value of which the appearances in the spectrum give us no clue.

Under these circumstances the best course would appear to be to frame
hypotheses as to what the motion of the electron is, and to find whether we can
think of any motion which would have elliptic partials with the periodicities,
forms, relative amplitudes, and directions of motion which the observations
indicate, and which would retain their periodic times through a great range
of temperature.

One naturally thinks first of the motion of an electron travelling without
friction along a prescribed path under the influence of a central attraction varying
directly as the distance. The curve to which it is trammelled being represented by

r = JcF{6\

the function F may evidently be such as to produce the observed series of lines ;
and if the dynamical conditions were such that F does not alter during the flight
of the molecule, k must diminish when energy is transferred to the surrounding

606

Stoney — Cause of Double Lines in Spectra.

aether. This represents a state of things under which, though the size of the curve
would dwindle during the flight of the molecule, the periodic times would remain
unaltered, and the lines in the spectrum unchanged in position. However, though
this agrees in many respects with what is observed, the conditions are evidently
not so simple, since under these conditions the lines of the spectrum, while fainter
at lower temperatures, would retain the same relative intensities at all temperatures,
which is not the case.

If the vortex theory of ponderable matter be true, it is in the study of the
dynamical, or rather kinematical, relations in, and in the neighbourhood of, vortex
rings and tangles, that we must put our hope. The vortex hypothesis, however,
would suggest charges of magnetic moment rather than of statical electricity as
associated with the atoms of ponderable matter. Perhaps both are present, and
that the electrical charges are maintained by motions of the magnetism. Some
motion of this kind must apparently be consequent on the velocity of over 30,000
metres per second with which the molecule, in common with the rest of the earth,
is travelling through the rectilinear vortices of the sether. We must remember,
too, that statical charges of electricity consist of motions or stresses not in the
molecules themselves but elsewhere. These considerations naturally suggest
others, but we need not follow them up, as it is unnecessary for our present
purpose to do so. This is fortunate, since we can as yet only grope in the region
which concerns itself with the fundamental facts of nature.

Whatever our ignorance on such subjects may be, one solid advance seems to be
harvested by the investigation in the foregoing pages. It has shown howto interpret
the spectrum of a gas when, as in the case of the monad elements, it consists of
double lines, so as to extract from the observations important particulars about the
several pendulous elliptic components of some of the motions going on within the
molecules ; it indicates the character and the limits of the information about these
motions which the spectroscope can supply ; and it puts us on the track of further
knowledge by guiding the hypotheses that we should frame. It also cannot fail to
impress upon us what an amazingly complicated system even one molecule of
matter is ; what an inconceivable number and variety of events are crowded into
every speck of space about us, within even the millionth part of one second of time ;
and how very little about nature is yet known to man.

In this branch of investigation we are wofully in want of more minutely exact
and fuller observations on the spectra of gases than have yet been published. It
may be hoped that there will be a great improvement in this respect when the
great work is published which has been recently announced by Professor Eowland
from the laboratory of the Johns Hopkins University.

Stoney — Cause of Double Lines in Spectra.

607

But this great work will lose much of its availability for such inquiries as the
present, unless it be accompanied by equally exact determinations of the refractive
indices of air throughout the spectrum. We cannot even verify Balmer's law
without these essential co-efficients.

POSTSCRIPT.

A good illustration of the time-relations of the motions that are concerned in the
production of spectral lines can be very simply made by screwing a small hook
into the middle of the lintel at the top of a doorway, and hanging a heavy bob
from it by a piece of silk or pack-thread of such a length that the middle of the bob
is 39 inches from the hook — about as long as an ordinary door is wide. The
oscillation period of this conical pendulum will be two seconds, the same as that
of a pendulum beating seconds.

Place a table in the doorway, and on it some kind of pointer, such as a candle
or bottle, supported by a box if necessary to make it reach nearly to the bob.

Now start the bob in a long (approximate) ellipse. We may take this to
represent the motion of the electron in a molecule of sodium, as it swiftly revolves
in that elliptic partial which produces the great yellow sodium line. The ellipse
of our conical pendulum will be seen to have an apsidal motion owing to the
resistance of the air. It is in the same direction as the revolution of the bob in
the ellipse. This is the right direction to represent the apsidal motion which takes
place in the molecule, but it is probably too swift. The apsidal circuit in our
apparatus may perhaps be completed in some five or ten minutes, whereas, to
correspond with the real event in the gas, it should take lh 6m 83 to get through
each revolution. Further, the bob parts with its energy to the surrounding medium
far too hastily, and will perhaps come to rest in less than an hour. It should be
able to persist in describing its orbit for several months, to be like the electron.
There is, however, no difficulty in making allowance for these defects. We should,
then, suppose the bob to be given a fresh impulse some eight or nine times every
fortnight, to represent on the time-scale that we have chosen the recurrence of the
encounters between the molecule and its neighbours, which from time to time
revive its internal motions. Finally we are to imagine our pendulum kept going
in this way without intermission for thirty-two years ; by which time the number
of the several representative events in the apparatus will have just accumulated up
to being the same as the number of the corresponding actual events that are going
on within each molecule of the vapour of sodium in every millionth of a second.

TEAUS. BOY. DTJB. SOC, N.S. VOL. IV., PAET XI. 4 E

608

Stoney — Cause of Double Lines in Spectra.

Another observation of general application seems worth making here. Each
molecule of gas at atmospheric pressures and temperatures, meets with about 7000
encounters in the millionth of a second, and of course those which fall to the lot of
one molecule must happen under a great variety of circumstances. Moreover,
immense numbers of these molecules are present, something like a thousand
millions* in every cubic micron of air ; while in the liquid state they are still more
numerous, about a thousand times as many of the gaseous molecules being now
crowded into each cubic micron. They are besides now jostled almost without
intermission, instead of each encountering its neighbours only at intervals, as in a
gas. There are therefore abundant chances for extremely rare circumstances to
occur in their struggles with one another, at what we should deem very short
intervals of time and space ; and it is probable that many important chemical and
physiological effects that appear to us to take place with even explosive prompti-
tude, have in reality to wait long (from the molecular standpoint) for their
appropriate opportunity to arise.

* See Phil. Mag. for August, 1868, top of page 141. Beaders of the Paper here referred to are
requested to change the square of 16, at the end of the second paragraph on p. 134, into the square root
of 16. The micron in use among microscopists is the thousandth part of a millimetre. About 70 or 80 of
the cubic microns would fit into one blood corpuscle.

NOTE ADDED IN PEESS.

Add the following footnote on p. 567 : —

See Tables, pp. 595-597, and a Diagram, p. 598, of the three series of double lines in the spectrum of
one of the light monad elements. The spectrum selected as an example is that of Sodium, and the spectra
of the others, viz. Lithium, Potassium, Euthenium, and Caesium, are of the same character.

|_ 609 J

XII.

A REVISION OF THE BRITISH ACTINIA. PART II.: THE ZOANTHESE.
By ALFRED C. HADDON, M. A. (Cantab.), M.R.I.A., Professor of Zoology, Royal
College of Science, Dublin ; and MISS ALICE M. SHACKLETON, B.A. Plates
LVIIL, LIX., LX.

[Read Febetjaey 18, 1891.]

CONTENTS.

PAGE

Introduction, 609

General account of the Anatomy of the Zoan these, . . . .612

Classification of the Group, . . ...... 626

Systematic Account of the British Zoanthese, ..... 634

Bibliography, ........... 663

Index, ............ 671

INTRODUCTION.

The first part of this Revision dealt with a new sub-family of the Sagartidae, the
Chondractininae, which included the genera Chondractinia, Hormathia, Chito-
nactis, Actinauge, and Paraphellia. A few notes were made on the genus Sagartia ;
and details are given of British representatives of Gephyra dohrnii. The British
members of the families Edwardsidse and Halcampidas were described ; and the
nature of Gonactinia prolifera was discussed. An account was also given of the
arrangement of the mesenteries in the Zoanthese. The Paper concluded with a
summary of the development of the mesenteries of Actinia ; and certain general
considerations were advanced on the phylogenetic value of the mesenteries.
Unavoidable circumstances caused this first part of the Revision to be heteroge-
neous in character, and unsatisfactory in many details.

The present instalment of the Revision is confined to a very distinct group of
the Actiniae. Although there has been considerable confusion within the group, the

TRANS. EOT. DUE. SOC, N.S. VOL. TV., PAST XII. 4 S

610 Haddon and Shackleton — A Revision of the British Actinice.

Zoanthese themselves have, since the time of de Blainville, been recognized as a
well-marked division of the Actiniae.

With the exception of the genus Sphenopus, and certain free varieties
of the genus Epizoanthus, all the members of this group are permanently
fixed, and with very few exceptions form colonies, the individuals of which
are united by the adhering base or ccenenchyme. The ccenenchyme extends
laterally, and from it new polyps arise, which remain permanently connected
with the colony.

The ccenenchyme may be band-like or form broad encrusting sheets ; usually
it is thin, but in the genus Palythoa it is so thick that the polyps are more or
less immersed within it. The polyps may be placed at considerable intervals
from each other, or they may be crowded together, the latter condition being
usually due to gemmation from the base of the polyps rather than from the
ccenenchyme.

It is characteristic of the group for the body-wall of the polyp and ccenenchyme
to be incrusted with foreign particles — grains of sand, spicules, foraminifera, and
such like. Some genera, such as Palythoa and Sphenopus, are always densel)
incrusted ; the incrustations in Parazoanthus vary according to the species from a
considerable amount to very few ; finally, the genera Zoanthus and Mammillifera
are unincrusted.

The Zoanthese have the same body-regions as other Actinia?, with the excep-
tion of the basal disc, which must necessarily be absent in the colonial forms, and
of a physa in the free forms. In all the column is divisible into scapus and
capitulum ; the former is usually rigid. In nearly all preserved specimens the
capitulum is retracted, and this appears to be generally the case when living, for
these forms do not fully expand so frequently as most other sea-anemones. The
capitulum is usually thrown into triangular ridges.

The tentacles are bicyclic, and may be very short or moderately long. When
fully expanded, the oral disc may be flat or projecting. The mouth is always
linear. Only one oesophageal groove is present.

The colours are usually various shades of yellow, buff, and brown, due to the
sand incrustations ; some have varied colours — pink, green, violet, and so forth —
but it is very rare for the colours to be so vivid as is customary among other
Actinias.

Eeproduction takes place by means of ova, by basal and ccenenchymatous
gemmation, and by fission.

The foregoing are all the characters which are available for the field
naturalist, and, until quite recently, were the only ones on which the definition
of species and their systematic arrangement were based. These purely external
characters are more than usually unsatisfactory for diagnostic purposes; hence

Haddon and Shackleton — A Revision of the British Actinice. 611

the not unnatural confusion into which the group has fallen, and from which it
has, to a certain extent, been extricated through the labours of Erdniann and
M°Murrich. In no group is it more necessary to combine anatomical and
microscopical examination with the methods of the older zoologists — for the
species of Zoantheae can only be established after sections have been cut and
studied. The identification of new material with recognized species requires
the utmost circumspection.

It is impossible to determine the genus to which many previously described
species belong until the types have been re-discovered, and then submitted to an
anatomical investigation. A complete monograph of the group is at present an
impossibility. We have, however, ventured as far as we safely could in this
direction.

We have investigated the anatomy of eleven species belonging to five genera
of Zoantheae from Torres Straits, besides several other forms, at the same time
that we were occupied upon the British representatives. Our Paper on the Torres
Straits specimens is published simultaneously with this one, and in the same
J ournal ; and we would ask those who are interested in this group to study both
Papers together, for the two are, to a certain extent, complementary to each
other.

Methods. — All the specimens examined by us were preserved in alcohol, and
when a sufficient quantity of strong alcohol is used this answers perfectly well.
We stained the objects whole in borax carmine, imbedded them in paraffin, and
cut them with a "rocking" microtome. In a few cases we stained the sections
after they were fixed on the slides.

The unincrusted genera are very easy to cut, and so are some of the incrusted
forms, especially some of the species of Parazoanthus. Those wishing to study the
anatomy of the group cannot do better than commence with P. axinellce, which is
very easily cut by the ordinary paraffin method. It was perfectly unnecessary for
von Koch to employ his " Schliff -methode " (Morph. Jahrb. vi., 1880, p. 359) when
investigating this species. We mention this solely to prevent others from taking
superfluous trouble. The different species of the genus Epizoanthus n.ro j clS tl rule,
difficult to sectionize, on account of the incrustations. E. paguriphilus is, however,
practically free from them ; owing to the great thickness of the mesoglcea in this
species, celloidin is a better imbedding material than paraffin, as heat has to be
employed in the latter method. As a rule, the incrustations in Zoantheae from coral
seas are calcareous, and admit of being readily dissolved away. We use nitric
acid for this purpose.

The use which we have made of the Papers of Erdmann and M°Murrich
will emphasize the indebtedness of students of the Zoantheae to those in-
vestigators. References to other workers will be duly acknowledged where we

4 S 2

612 Haddon and Shackleton — A Revision of the British Actinice.

utilize their results. The laborious monograph of Andres has been in constant
requisition.

It is now our pleasing duty to acknowledge the assistance of many friends.
The Rev. Canon. A. M. Norman and Professor W. C. M'Intosh have generously
placed the whole of their collections at our service ; and it is due to the considerable
number of foreign (Mediterranean and North Atlantic) specimens belonging to the
former that we have been enabled to determine several non-British species. The
Director of the Marine Biological Laboratory at Plymouth, and Mr. G. Y. Dixon
have also supplied us with specimens, as have also our foreign colleagues,
Drs. D. C. Danielssen and J. Playfair M°Murrich. Finally, we have to thank
Dr. E. Perceval Wright for the loan of books and for ready assistance in the
solution of taxonomic and synonymic difficulties.

GENERAL ACCOUNT OF THE ANATOMY OF THE ZOANTHEiE.

The main external characters of the Zoanthese have already been given in the
Introduction ; and before giving a detailed account of the anatomy of the group it
will be necessary to say a few words as to the anatomy of these Actiniae.

As in other Actinozoa, the body- wall is composed of three layers : the ectoderm,
the mesoglcea, and the endoderm. There is now no need to adduce arguments in
favour of the employment of the second of these terms.

The mouth leads into a rather short oesophagus or stomatodseum, the walls of
which are often thrown into folds ; at one end a distinct and sometimes a very
deep groove is present, for which one of us has suggested the name of " sulcus," or
sulcar groove. Projecting into the cavity, or ccelenteron of the polyp, from its
body- wall, are a number of soft plates which are known as mesenteries; sometimes
these are called " sarcosepta," and occasionally they are erroneously spoken of as
" septa." The employment of the latter term cannot be too strongly deprecated as
leading' to confusion with the septa, or calcareous radial partitions of the Madre-
poraria.

The mesenteries of the Zoanthese fall under two categories —

(1) The large mesenteries which extend from the body- wall to the stomato-
dseum, and which alone bear mesenterial filaments and gonads. These are the
"perfect mesenteries" or "macrosepta" of authors.

(2) The small mesenteries which extend only slightly from the body- wall into
the coelenteron, and which are sterile, and do not bear mesenterial filaments.
These are the " imperfect mesenteries " or " microsepta."

As in most Actinias a pair of mesenteries occurs at each end of the oesophagus ;
these are usually spoken of as the " directives," or " directive mesenteries."

Haddon and Shackleton — A Revision of the British Actinice.

613

The mesenteries which yield such a valuable aid to classification in the
Actiniae generally are arranged in this group in a very uniform manner.

In the first part of this revision (1889, p. 343), a short account is given of the
history of the elucidation of the arrangement of the mesenteries in the Zoanthese.
Since this was written the second part of Hertwig's " Challenger " Report has been
published, without, however, adding anything to Erdmann's account. M°Murrich
has also written two valuable Papers (1889 and 1889 a), but no new type of mesen-
teric arrangement has been described beyond those first pointed out by Hertwig
(1882), and properly described by Erdmann.

It is necessary to have a recognized system of terminology in order to describe
the arrangement of the mesenteries in the Actinias ; and it is advisable to have
such a terminology as is applicable to the whole of the Actinozoa. One of us has
already (1889) proposed the adoption of certain terms, and the abolition of others
which have not a precise meaning — as, for example, such words as " dorsal" and
"ventral," these latter were replaced by "sulcular" and "sulcar," respectively.
When only one axial oesophageal groove is present, it is usually (? always) the
sulcar. In the same Paper attention was called to the value of the order of the
appearance of the mesenteries in young Actinias, as suggesting the affinities of
different groups of sea-anemones. The following diagram illustrates the pro-
posed method of naming the mesenteries and chambers at a stage when twelve
mesenteries have made their appearance : —

Sulcular endocoele

Sulcular exocoele

Sulculo-lateral endocoele

Lateral exocoele

Sulco-lateral endocoele

Sulcar exocoele

Sulcar endocoele

Examples. — Edwardsia has a pair of sulcular and a pair of sulcar directives ; a
sulculo-sulcular lateral mesentery, and a sulculo-sulcar lateral mesentery on each
side, all of which are perfect.

The larval form of Zoanthus has a pair of sulcular imperfect directives and a
pair of sulcar perfect directives ; a sulculo-sulcular lateral perfect mesentery, a
sulco- sulcular lateral imperfect mesentery, a sulculo-sulcar lateral perfect mesen-
tery, and a sulco-sulcar lateral imperfect mesentery on each side.

■ Sulcular directives.

.Sulculo-sulcular lateral.
Sulco-sulcular lateral.

.Sulculo-sulcar lateral.
Sulco-sulcar lateral.

.Sulcar directives.

614

HADDON AND SnACKLETON

— A Revision of the British Actinia;.

The larval form of Epizoanthus agrees with Zoanthus, except that the sulco-
sulcar lateral mesenteries are perfect.

In the Zoan these new mesenteries appear in the sulcar exocoeles in such a way
that the mesenteries nearest the sulcus are the youngest, and those furthest from it
the eldest.

In the Sagartidse the new mesenteries appear in pairs in all the exocoeles.

The mesenterial filaments, the gonads, the mesenteric canals, and the ccenen-
chyme will be dealt with later on. We will now proceed to describe the structure
of the Zoanthese in greater detail in the following order : —

Body-ivall — ectoderm, incrustations; mesoglcea, cell-enclosures, endodermal
bays, ectodermal bays ; endoderm, diffuse endodermal muscle, sphincter muscle ;
capitulum.

Tentacles and Disc.

(Esophagus.

Mesenteries. — Imperfect mesenteries, perfect mesenteries, reflected ectoderm and
mesenterial filaments, mesoglcea, canals, endoderm, muscles, gonads.

Coenenchyme.
Development.
Parasites.

Body-wall. — Ectoderm. — The ectoderm is very liable to be rubbed off in the
incrusted genera ; where present it generally appears as a continuous layer of
narrow columnar cells. In the unincrusted genera, in Gemmaria macmurrichi
and in Epizoanthus paguriphilus, the ectoderm is traversed by strands of
mesoglcea, which unite to form a layer peripheral to the ectoderm, and which,
in some species break up the ectoderm into more or less cubical blocks (PI. lix.,
fig. 6).

External to the ectoderm there is always a cuticular layer which may be very
thin, and stains of a darker colour [Parazoanthus dizo7ii, PI. lix., fig. 9), or it may
be thick, in which case it rarely stains, and is often impregnated with dirt
(Epizoanthus wrightii, PI. lix., fig. 3).

As the cuticle is an ectodermal secretion in forms with a continuous ectoderm,
and, as the peripheral layer of mesoglcea must also be of ectodermal origin, and is,
as a matter of fact, often indistinguishable from the cuticle, we do not consider it
of any importance to discriminate between them in the forms with discontinuous
ectoderm.

The above-mentioned layer of mesoglcea, peripheral to the ectoderm, is that
which is called the subcuticle by Andres (1877, p. 222).

The ectoderm usually contains nematocysts, which McMurrich and others have
failed to observe. As a rule these do not stain readily. In some species they are
clear; in others — e.g. E. norvegicus (PI. lix., fig. 5), where they are, by-the-by,

Haddon and Shackleton — A Revision of the British Actinia? . 615

unusually numerous — they contain pigment granules. In E. paguriphilus they are
very dark ; often they have a yellowish colour, and are somewhat opaque.

Zooxanthellae are present in the ectoderm of the three species of Isaurus which
have been microscopically examined, and in many other species of the Brachy-
cneminsB, but apparently not in all. We have not found them in any of the
Macrocneininae.

Incrustations. — The incrustations which form such a characteristic feature of
this group of Actiniae are absent in the genera Zoanthus and Isaurus, though very
rarely a stray spicule, or grain of sand, may be entangled in the cuticlar layer of
these genera.

With regard to the other genera, according to our experience, it appears that
certain species have a proclivity for a particular kind of incrustation. The
character of the incrustation must be conditioned by the precise habitat, i. e. whether
sand-grains are calcareous or siliceous, or, again, whether the bottom is sandy or
stony ; if sponges are abundant on a rocky bottom (as, for example, in Albany
Pass, Torres Straits), the forms will probably largely make use of sponge-spicules,
as in Parazoantha douglasi. The best example we have of apparent selection is in
the case of Epizoanthus incrustatus ; of this species we have cut specimens from
Norway, Shetland, West of Ireland, and N. E. America (E. americanus, Verrill), and
in all cases we find the incrustations to be composed almost entirely of grains of
sand. In the single specimen, we have been able to examine, of E. macintoshi,
from Shetland, the incrustations are almost entirely Foraminifera. In Norman's
type specimens of Parazoantha anguicoma, from Shetland, the incrustations include
grains of sand, Foraminifera, and sponge spicules ; this holds good for the same
species from the West of Ireland, as well as for the other species (P. dixoni) from
the same district.

The amount of incrustation also varies — for example, the species of Epizoanthus
are usually thickly incrusted, but in Epizoanthus paguriphilus the incrustations are
very few in number. In Parazoanthus dichroicus there are very numerous incrus-
tations, but in P. axinellw they are sparse, and in P. dixoni there are still fewer.

Mesoglcea. — 'The mesogloeal ground substance is always homogeneous ; it is
penetrated by numerous minute cells, which are sometimes star-shaped, but more
frequently produced at each end into a long fibril which extends in a radial direc-
tion. Some of these fibrils are undoubtedly connected with the ectoderm, and
others with the endoderm (PI. lxiv., fig. 1)* ; it is impossible to determine whether
some may not stretch right across the mesogloea. We have not been able to
satisfy ourselves of their presence in every case (ex. E. wrightii).

* Plates lxi. to lxiv. will be found in the Memoir of these Transactions immediately succeeding this
one, viz. that on the Zoantheae of Torres Straits. They are frequently referred to in the present account
of the anatomy of the group.

616 Haddon and Shackleton — A Revision of the British Actiniae.

Cell enclosures. — Large ectodermal canals, penetrating the rnesoglcea, are very
characteristic of the genus Zoanthus ; they also occur in Parazoanthus. In
Z. coppingeri there are numerous large anastomosing canals which arise from
the ectoderm (PI. lxii., fig. 1), and have a general radial direction; many of the
canals pass into the mesenteries.

In Isaurus the canals are relatively much smaller than in Zoanthus, and are
more broken up than in Z. coppingeri, and undoubtedly have an endodermal as
well as an ectodermal origin (PI. lxiii., figs. 5 and 6).

The chief feature of the canal system in Parazoanthus is the presence of an
encircling sinus, which lies just beneath the endoderm, and extends throughout the
whole body-wall. This sinus is not everywhere continuous, but is frequently
crossed by bars of rnesoglcea (PI. lix., fig. 8). It is connected with the ectoderm
by radial, occasionally branched canals. In P. anguicoma and P. dizoni, and in some
other species, very fine canals connect the sinus with the endoderm (PI. lix., fig. 9).
Although the encircling sinus may have connexions with the endoderm, these are
very delicate, and the sinus itself is undoubtedly of ectodermal origin. The
encircling sinus is the same as the "ring-canal" described by Erdmann in his
" sp. 8 Palythoa sp." (1885, p. 469). [This is the Palythoa anguicoma of Hertwig,
which we believe to be another species, for which we would suggest the name
Parazoanthus hertwigi.~\ Nematocysts are present in the canals of many of the
species of Zoanthus and Parazoanthus ; possibly th.ey are of universal occurrence
in the canals.

In Gemmaria macmurrichi a somewhat similar encircling sinus is present, but it
is very largely broken up by the rnesoglcea into a number of vertical canals which
appear in transverse section as a series of lacunas, each one lying immediately
below the union of a mesentery with the body-wall (PI. lxiii., fig. 7). These
vertical canals are often connected by finer ones.

Lacunae are found in all the genera of the Zoanthea? except Epizoanthus and
Sphenopus. In Zoanthus it appears that the canals are more or less broken up to
form the lacuna?., least so in Z. coppingeri and Z. dance (as identified by Hertwig),
and most so in Z. jukesii (PI. lxii., fig. 2), in which species continuous canals are
rare ; the same also obtains in Isaurus asymmetricus. In Palythoa there are no
continuous canals ; but lacuna? are present, as these are so similar to those which
we know to be of ectodermal origin in other species ; and as nematocysts are
present, we believe that these lacuna? are of ectodermal origin (PI. lxiii., figs. 8
and 9).

Small groups of cells, irregularly scattered in the rnesoglcea, are especially
characteristic of the genus Epizoanthus ; they may be very numerous, as in E.pagu-
riphilus (PI. lix., fig. 6), and in some of the species described by Erdmann, but in
other species, E. incrustatus, E. couchii, and E. wrightii, they are very rare. They

Haddon and Shackleton — A Revision of the British Actinias.

617

are abundant in the Parazoanthus dichroicus, and are also common in P. anyuicoma,
and P. douglasi. They occur also in Gemmaria macmurrichi, Palythoa howesii, and
P. kochii.

We have no proof that these small and isolated groups of cells, which have
been aptly termed "cell-islets" (" Zellinseln ") by Erdmann, are connected in
any way with the canals or the lacunae, and, like that investigator, we do not
know their origin. We regard these islets as simply groups of ordinary meso-
glceal cells.

Endodermal and ectodermal bays. — We may here refer to the endodermal bays
described for Isaurus [" Mammillifera"^ tuberculatus by McMurrich (1889, p. 118);
he says: "In some of my sections deep bays can be seen running from the
endoderm into the mesoglcea, and from their ends and sides numerous canaliculi
can be seen branching out. These bays can be found in various states of enclosure
by the mesoglcea, the cells which they contain being in some cases continuous
with the general endoderm, in other cases almost separated from it, and finally
quite so. So, too, with the ectoderm." We have found similar deep endodermal
bays in Isaurus asymmetricus (PI. lxiv., fig. 9), but in no case were the bays quite
separate from the general endoderm. In our species the ectodermal bays (PI. lxii.,
fig. 4) differ considerably from those of M°Murrich's species ; the latter we have
been able to examine through the courtesy of our friend, and as he has not
figured one of these bays we add one for comparison (PI. lxiil, fig. 3).

Endoderm. — The endoderm of the body -wall presents few features worthy of
remark. In I. asymmetricus we have found nematocysts smaller than those which
occur in the ectoderm. Zooxanthellae are present in the three species of Zoanthus
from Torres Straits, and appear to be characteristic of this genus as well as Isaurus.
They are also extremely numerous in G. mutuki, and are present in Palythoa
howesii and P. kochii. In Parasoanthus dixoni the endoderm is thickened into ridges
between the mesenteries, but in most cases it is of uniform thickness.

Diffuse endodermal muscle. — The base of the endoderm forms a feeble but
complete muscular sheath ; as the fibres run in a horizontal direction, the muscle
is scarcely to be seen in transverse sections ; in vertical sections (PI. lix., figs. 9
and 12) they are readily seen.

Sphincter muscle. — The diffuse endodermal muscle of the general body-wall
becomes converted in the capitular region into a sphincter muscle, which in contrac-
tion causes the introversion of the corona and capitulum. The genus Parazoanthus is
unique amongst the Zoantheaa in possessing an endodermal sphincter. This fact
was first discovered by Erdmann (1885, p. 468), who made this a primary character
in the definition of his interpretation of the genus Palythoa, of which he took
P. axinellw as the type. As we shall subsequently explain, Erdmann' s genus
Palythoa cannot stand ; so we have erected the new genus of Parazoanthus in its

TRANS. EOT. DUB. SOC. N.S. VOL. IV., PAET XII.

618 Haddon and Shackleton — A Revision of the British Actiniae.

stead. The infoldings of the endodermal sphincter, especially in its upper portion,
are frequently so cut across by the razor in sections as to appear isolated, and thus
the muscle might be supposed to be partly mesoglceal in character (PL lx., fig. 8).
It is possible that this may actually occur to a very slight extent. In either case
the distinction between Zoantheae with an endodermal and a mesoglceal sphincter
is not so fundamental as might appear at first sight.

All other Zoantheae have a mesoglceal sphincter. In Sphenopus the sphincter
is extremely long, as Erdmann has previously remarked ; Zoanthus alone has a
double sphincter (PL lxiv., figs. 3 and 5).

Capitulum. — The capitulum, as all authors have described, is thrown into
ridges ; these have a certain amount of specific value, but too much reliance
should not be placed upon this character.

In all species the ectoderm retains its character as a continuous epithelium.
In Z. coppingeri the ridges are crowded with nematocysts, but we do not find this
of common occurrence.

Tentacles. — The ectoderm of the tentacles contains numerous sausage-shaped
nematocysts. The deeper layer of the ectoderm usually exhibits a well-marked
nervous layer, the nerve-cells of which are shown in PI. lxiv., fig. 2. There is
a diffuse ectodermal muscular sheath, the fibres of which have a longitudinal
direction.

The mesogloea is usually thin. The endoderm is relatively thick ; and in Z.
coppingeri, Z. jukesii, &ndZ. macgillivrayi zooxanthellae are here especially abundant,
but in /. asymmetricus and in Palythoa howesii and P. /cochii, although they are
present in the endoderm of the body- wall, few, if any, are to be found in this region.
In Z. coppingeri numerous nematocysts of oval shape, similar to those found in the
ectoderm of the body-wall, are present in the endoderm of the tentacles (PL lxiv.,
fig. 2). And in some of our specimens of E. couchii similar nematocysts are to
be found in the ectoderm of the tentacles. A diffuse endodermal muscular layer
consisting of fibres which run in a circular or horizontal direction, and which may
be regarded as an extension of the muscular layer of the body-wall, is found in the
tentacles of all our species.

Disc. — The structure of the disc is usually similar to that of the tentacles. As
in the latter, there are no incrustations.

(Esophagus. — The ectoderm of the oesophagus is usually more or less folded ;
but as the degree of folding is variable in different individuals of the same species,
and probably also in the same individual in different conditions of contraction,
this character is of little value for systematic purposes. The same may be said of
the nature and extent of the groove. A sulcar groove is always present, but it is
scarcely discernible in our specimens of /. asymmetricus, and in one of the specimens
of E. incrustatus (PL lx., fig. 1). In other specimens of the latter species it is,

Haddon and Shackleton — A Revision of the British Actiniae. 619

however, distinct. Nematocysts are found in the ectoderm of the oesophagus of
Palythoa ccesia (?), E. couchii, and E. arenaceus.

The mesoglcea of the oesophagus is generally thin, but in many species of
Epizoanthus and of Parazoanthus it is much thickened in the groove. Cell enclosures
are generally absent in this region, but we have seen a few cell-islets in the
mesoglcea of the groove of P. anguicoma (one specimen), and they are also present
in that of P. dichroicus.

Mesenteries. — The mesenteries which are such a valuable aid to classification of
the Actiniae generally are arranged in this group in a very uniform manner, which
we have already described.

Imperfect mesenteries. — The imperfect mesenteries vary in the extent to which
they project into the ccelenteron. In E. incrustatus, and in Parazoanthus douglasi
they are very small, whereas in P. dixoni they are well developed. When canals
are present in the perfect mesenteries they are also to be found in the imperfect.

Perfect mesenteries. — There is no distinction between any of the perfect
mesenteries.

Ectoderm. — The presence of ectoderm in certain mesenteries of the Anthozoa
appears to be now fairly well established. E. B. Wilson (" Mesenterial Filaments
of the Alcyonaria": Mitth. Zool. Stat. Neapel, v. 1884) came to the conclusion
that the " dorsal " pair of filaments in the Alcyonaria were ectodermal in origin,
but that the other six filaments were solely endodermal ; these two kinds of
filaments can be readily distinguished histologically. Some years previously von
Heider (Cerianthus membranaceus, Haime : Sitz. kais. Acad. Wien, lxxix. 1879)
believed, solely from a histological study of the adult Cerianthus, that the filaments
of that form were ectodermal. The Brothers Hertwig (Die Actinien, 1879)
pointed out that embryological deductions based on adult histology were not very
reliable, and also brought forward, as an objection to von Heider's view, the
existence of filaments on imperfect mesenteries in the Actiniae generally. H. V.
Wilson (Journ. Morph. n», 1888) has shown for the coral Manicina, and J. P.
McMurrich (ibid. iv. 1891) for the Actinian, Rhodactis, that the mesenterial
filaments are derived from the ectoderm of the oesophagus.

From the histological characters and absolute continuity of what we have
termed the "reflected ectoderm" of the mesenteries with the ectoderm of the
oesophagus on the one hand, and with the mesenterial filament (craspedum) on the
other, we have no doubt as to the morphological identity of these tissues.

Reflected Ectoderm and Filaments. — The mesenteric ectoderm consists of two
portions, an upper, which we speak of as the Ci reflected ectoderm," and a lower
portion, which runs down the edge of the mesentery, and is known as the mesen-
terial filament, or " craspedum " of Gosse. These two are perfectly continuous
with each other and with the ectoderm of the oesophagus.

620 Haddon and Shackleton — A Revision of the British Actinice.

In looking at a side view of a mesentery such as that of Z. macgillivrayi (PI. lxiv.,
fig. 5) it will be seen that the ectoderm of the oesophagus passes continuously on
to the mesentery where it suddenly becomes greatly thickened, and is thrown into
transverse folds ; the whole thickening has a crescentic form, first coming upwards
and then downwards losing itself in the mesenterial filament. The ectoderm is
reflected on both sides of every one of the perfect mesenteries (PI. lx., fig. 6),
and presents a very characteristic appearance in transverse sections (PI. lxiv.,
figs. 4 and 6). The folds often present a pinnate appearance, but they are rarely
accurately symmetrical on each side.

In some species the endoderm is implicated in the upward reflection of the
lower edge of the oesophagus ; this is especially noticeable in Parazoanthus axinellce
(PI. lx., fig. 6), but it is not a feature of any morphological importance.

As above mentioned the reflected ectoderm passes gradually into the mesen-
terial filament. The characteristic trefoil (P. axinellce) (PI. lx., fig. 6) or V-shape
[Z. macgillivrayi) (PI. lxiv., fig. 7) of the latter in transverse sections is continuous
with the peripheral pair of folds of the reflected ectoderm.

The lateral elements of the upper portion of the craspedum gradually become
shorter, so that eventually only the median portion is left (PI. lx., fig. 7). This
transition takes place very shortly below the lower level of the oesophagus.

Nematocysts are numerous in the simple lower portion of the mesenterial
filament ; but they are not readily seen in the upper portion, and we have not
observed any in the reflected ectoderm. Unicellular glands and pigment granules
also occur in the filament.

The length of the craspeda varies even in the same genus, it apparently being
dependent upon the height of the polyp ; for example in Z. jukesii, which is a
short species, the filaments extend nearly down to the commencement of the
ccenenchyme, whereas in Z. macgillivrayi they cease about half way down the
polyp.

Mesoglcea. — The mesogloea of the mesenteries exhibits a certain amount of
variation in thickness ; for example, in the oesophageal region of Parazoanthus
dixoni (PI. lx., fig. 9), the mesogloea is relatively thick, whereas in Epizoanthus
paguriphilus (PI. lx., fig. 5) it is quite thin.

Canals. — In describing the canals in the mesoglcea of the body-wall, we have
already alluded to the fact that in the three species of the genus Zoanthus from
Torres Straits which we have examined, they not only arise from the ectoderm,
but pass into the mesenteries.

Hertwig (1882, p. 115) describes in Z. dance (?) (cf. 1888, p. 36) a basal
" septal canal " "in the supporting lamella of the septa in immediate proximity
to the wall." He "never could make out any connexion between this septal
canal and the ectodermal cords [*. e. canal system] of the wail " ; and he is

Haddon and Shackleton — A Revision of the British Actiniae. 621

" inclined to believe that it is produced from the endoderm." His reason is that the
zooxanthellse, which are found in the mesenteric canal of this species, " force their
way into the septal canal, but never into the canals of the wall." According to our
experience there are no connexions between the canal-system of the body-wall and
the mesenteric canals in the oesophageal region of the body, although they are
numerous lower down. The section Hertwig figures is from the oesophageal region.

M°Murrich (1889a, p. 64) finds in Z. sociaius, in "one mesentery, the basal
canal communicating with one of the spaces in the mesoglcea of the column
wall." He adds: "It seems open to question whether the cells of the larger
cavities in the mesoglcea are not in reality endodermal in their origin." In his
subsequently written, but previously published Paper (1889, p. 114), in alluding
to the body-wall canals of Z. flos-marinus, he refers the reader to his description
of Isanrus [" Mammillifera"~\ tuberculatus for his views as to the origin of these
canals, evidently believing that the " endodermal bays" of the latter species give
rise to some of the canals, the remainder being similarly derived from the
ectodermal bays, and then not unnaturally concludes that the mesenteric canals
are connected only with the endodermal " spaces " of the body-wall. We have
corroborated M°Murrich's observation as to the double origin of the canal-system
in the body-wall of Isaurus; but we have no reason for supposing that the canals
in the mesenteries are without exception of endodermal origin, although some
undoubtedly are (PI. lxiii., fig. 5). Our experience leads us to the conclusion that
it is necessary to be cautious in arguing as to the origin of these canals from one
genus to another. For confirmation of our view, that the mesenteric canals of
Zoanthus are of ectodermal origin, we point to the demonstration of this fact for
Z, coppingeri (PI. lxii., fig. 1).

In Z. coppingeri the canals form at the base of each mesentery a large sinus,
which extends up the mesentery, nearly to the generative region , where it rapidly
narrows, and extends right up the mesentery as the "basal canal." In Z.jukesii
and in Z. macgillivrayi the mesenteric canals are present, though not forming
extensive sinuses (PI. lxii., fig. 2).

In /. asymmetricus the canal system appears in sections as if broken up into
lacunae ; but it may really form a continuous system of anastomosing canals.

In Gemmaria rusei (1889, p. 125) and G. isolata (1889 a, p. 66) the mesenteric
canal, according to M°Murrich, has the character of a basal canal. We find the
same in our two species. Sinuses, extending throughout the whole length of the
mesenteries, occur in the three species of Palythoa we have examined. So far as
our experience goes canals are absent from the mesenteries of Epizoanthus, and the
same obtains for all the species of Parazoanthus except P. anguicoma and P. dixoni,
in which species we have found sinuses in the bases of the mesenteries which have
a slight vertical extension.

622

Haddon and Shackleton — A Revision of the British Actinice.

In Parazoanthus dichroicus cell-islets occur in the mesoglcea of the mesenteries,
and also in E. paguriphilus.

Nematocysts are sometimes present in the canals and sinuses of the mesenteries
{e.g. Z. coppingeri (PI. lxii., fig-. 1) and Palythoa howesii) ; but zooxanthellse are
rarely present. We have found them in Palythoa Jcochii.

Endoderm. — The endoderm of the proximal portion of the mesenteries usually
resembles that of the body-wall, except that it more frequently contains nematocysts,
as in Z. coppingeri, Z. macgillivrayi, and I. asymmetricus. In the latter species they
are much smaller than those of the ectoderm of the body-wall. Zooxanthellse
occur in the endoderm of the mesenteries in those species in which they are
present in the general endoderm.

M°Murrich has carefully described the swollen distal portion of the endoderm
of the mesenteries of Z. flos-marinus (1889, p. 115, PI. vii., fig. 4) in that region of
the body where the mesenterial filament is simple. We have found a similar
enlargement in Z. macgillivrayi (PI. lxiv., fig. 8), in which nematocysts are present.
Our specimen differs from his chiefly in the possession of zooxanthellse and
nematocysts ; we have not observed in our species that these endodermal cells
are " loaded with green granules, closely packed together."

A similar swelling occurs, to a variable extent, in other species ; for example,
in P. azinellce (PI. lx., fig. 7) it is only moderately developed, and we have not
observed nematocysts or zooxanthellae ; but these appear to be absent in the
general endoderm of this species. Sometimes the swelling is absent, as in E.
incrustatus.

We, too, have found, with M°Murrich, "foreign bodies of organic nature
imbedded in the cells, sometimes being surrounded by a number of cells containing
no granules, or occasionally imbedded in the mesoglcea" (1889, p. 116). He
suggests that these are concerned with digestion (PI. lxiv., fig. 8).

Muscles. — The muscles of the mesenteries are endodermal and diffuse. As in
other Actiniae there are two kinds of muscles, the longitudinal and the parieto-
basilar.

The longitudinal muscle is often very difficult to distinguish in transverse
section, being feebly developed, and forming a simple layer of fibres (PI. lxiv.,
fig. 8). In /. asymmetricus and E. paguriphilus, Parazoanthus dixoni, and others, the
muscle is better developed, and is slightly plaited (PI. lx., fig. 9).

The parieto-basilar muscle is usually relatively broader, and extends higher up
the mesenteries than in other Actiniae ; but in Parazoanthus anguicoma and P. dizoni,
this muscle is very feebly developed, and only occurs at the insertion of the
mesenteries (PI. lx., fig. 9).

It has been recognized by other investigators that judging by the arrange-
ment of the muscles the mesenteries of the Zoantheae are paired, although the

Haddon and Shackleton — A Revision of the British Actinice. 623

two elements of each pair are respectively a perfect and imperfect mesentery, and
are independently developed. Recently, however, Danielssen (1890) has thrown
doubt upon this paired arrangement, since he finds in the various species he has
examined that the muscles are equally developed on both sides of the perfect
mesenteries. Owing to the kindness of our Norwegian colleague we have been
enabled to examine some specimens of Epizoanthus [" MardoelV^ erdmanni, and our
sections show this paired arrangement quite clearly.

Gonads. — There appears to be a general impression that all the Zoanthese are
hermaphrodite. This is certainly not the case in four genera ; of one genus we
have no facts either way, and in the the remaining two genera the sexes may be
distinct or united. Generative organs often appear to be absent in specimens of
Zoanthese, but we have been somewhat fortunate in finding them in those
we have examined. Their mode of occurrence will be seen on reference to the
Plates in this and in the Memoir on the Zoanthese from Torres Straits.

Erdmann found that the two species of Zoanthus which he examined ("1 sp.
Zoanthus sp. ?," p. 438 ( = Z. dance [?], Hertwig) ; and "2 sp. Z. sp. ?," p. 447)
were hermaphrodite, so he concluded that this was a generic character. McMurrich
found no generative organs in the two species he examined. Of the three
species we have examned, two specimens of Z. coppingeri were male and three
were female ; two specimens of Z. jukesii were female, and of the four specimens of
Z. macgillivrayi we sectionized none were fertile. The conclusion we arrive at is
that the genus is as often dioecious as monoecious.

M°Murrich found that Isaurus \_u Mammillifera "2 tuber culatus was hermaphro-
dite, and owing to his courtesy we have been enabled to verify this fact. We
have cut several specimens of our I. aspnmetricus, but in only one of them could
we discover generative organs, and in this case they were feebly developed ova.
We cannot, however, assume that the genus is hermaphrodite because one
species is undoubtedly monoecious.

All the remaining genera, so far as is known, are dioecious, except Sphenopus,
the gonads of which are unknown.

Neither Erdmann nor M°Murrich found generative organs in the five species
of Palythoa (" Corticifera ") examined by them. We have been more fortunate,
since in P. kochii we found male organs alone, and in P. howesii we found only
female.

According to our experience all the members of a single colony of dioecious
Zoanthese belong to the same sex ; but we cannot lay down any general rule on
this point.

Coenenchyme. — The structure of the coenenchyme is similar in every respect to
that of the polyps. The only difference consists in the presence of ccelenteric
canals, which are merely prolongations of the ccelenteron of the polyps.

624 Haddon and Siiackleton — A Revision of the British Actinia}.

The ccenenchyme may occur as stolons, more or less riband-like, or as flattened
expansions, or, as in Palythoa, it may fill up the intervals between the polyps.
Some zoologists have laid stress on the systematic value of the habit of growth of
the ccenenchyme ; but, as a matter of fact, we have often found that in the same
species it varies according to the surface to which the colony is attached, and
therefore cannot lay great stress on this character. The genus Gemmaria, as
defined by M°Murrich, precisely resembles Palythoa (his Corticif era), with the
exception of the character of the ccenenchyme, it being absent or lamellar in the
former. We consider this a legitimate use of the character of the ccenenchyme
for taxonomic purposes.

The most interesting varieties of ccenenchyme occur amongst those species of
Epizoanthus which incrust Gasteropod shells inhabited by hermit crabs. In these
cases the ccenenchyme dissolves the lime of the shells, which it replaces by its own
substance; and thus the carcinsecium practically forms an isomorph of the shell.
The spire of the shell is the last portion to be absorbed. In describing the manner
in which the polyps are arranged on the ccenenchyme, we employ the terms
"dorsal," "ventral," "anterior," "posterior," "right," and "left;" these have
reference solely to the position of the carcinaecium with regard to the crab when
walking.

Development. — We have no account of the development of any Zoanthean, with
the possible exception of an observation by Van Beneden (1890), who describes
the anatomy of a larval Actinozoon allied to Semper's larva (Zeitschr. f. wiss Zool.,
xvii. 1867). He regards it as a larva of a " microtypal " (brachycnemic) Zoanthean,
on account of the arrangement of the mesenteries. He adds: "What further
confirms our opinion, that our larva and that of Semper may be connected with
the development of the Zoanthese, is that the constitution of the mesenchymatous
lamella is particularly well developed, and provided with numerous cellular
elements, of which some have an endodermic origin, the others being derived
from the ectoderm" (p. 95). The senior author has very recently (Proc. Roy.
Dub. Soc. (N. S.), vol. vii., pt. m., p. 127, 1891) published a small Paper on a larval
stage of the coral Euphyllia, which presents many of the anatomical peculiarities
which characterise Van Beneden's larva ; it is only fair to add that in the
newly-hatched larva of Euphyllia the mesoglcea is thin and without cell-
enclosures.*

Parasites. — Some of our specimens of Parasoanthus douglasi from Albany Pass
are infested by a Copepod which deposits its egg- capsule in the ccelenteron or

* Since the above was in type we have received, through the courtesy of the author, a valuable Paper
on "The Phylogeny of the Actinozoa," by Professor Mc]tfurrich (1891), in which he gives an account,
and four figures (PI. ix., figs. 5-8), of two stages in the development of a brachycnemic Zoanthean. "We
regret we can do no more than draw attention to this Paper.

Haddon and Shackleton — A Revision of the British Actiniae. 625

ccelenteric canals of the Zoanthean. The capsules are paired, and contain a large
number of ova. We have these in the nauplius stage, and in other stages of
development. We have two specimens of the Copepod, but are unable to say
whether these are adult or not. The capsules form distinct swellings (PI. lxl,
figs. 19-22) of the body- wall of the Actinian. This fact leads us to suppose
that the Copepod remains within the coelenteric cavities while the capsule is
developing ; and when the latter is ripe it breaks away from it.

We have sections of a Crustacean in the ccelenteron of the only specimen of
Episoanthus macintoshi (from Shetland) we were able to cut, but we cannot say
anything more about it.

Small, oval, deeply pigmented bodies occur in many parts of the body in
Parazoanthus dichroicus and in P. douglasi (PI. lxil, figs. 5 and 6). They are
evidently parasites, but we have been unable to determine their nature.

Problematical rounded bodies, which stain deeply and uniformly with carmine,
are present in Z. macgittivrayi, Palythoa howesii, and other species.

THANS. HOT. DOB. 80C, N.8. VOL. IV., PAET XII.

626 Haddon and Shackleton — A Revision of the British Actinice.

CLASSIFICATION OF THE GROUP.
ZOANTHEiE.

Actiniae with numerous perfect and imperfect mesenteries, and two pairs of
directive mesenteries, of which the sulcar are perfect and the sulcular are imperfect.
A pair of mesenteries occur on each side of the sulcular directives, of which the
sulcular moiety is perfect and its sulcar complement is imperfect ; a similar second
pair occurs in one section of the group (Brachycneminse), or the second pair may
be composed of two perfect mesenteries (Macrocneminse). In the remaining pairs
of mesenteries, of both divisions, this order is reversed, so that the perfect
mesentery is sulcar and the imperfect is sulcular. The latter series of mesenteries
are bilateral as regards the polyp and arise independently (i. e. neither in pairs nor
symmetrically on each side) in the exoccele on each side of the sulcar directives,
in such a manner that the sulcular are the oldest and the sulcar the youngest.
Only the perfect mesenteries are fertile or bear mesenterial filaments. A single
sulcar oesophageal groove is present. The mesogloea of the body -wall is traversed
by irregularly branching ectodermal canals or by scattered groups of cells. The
body-wall is usually incrusted with foreign particles. The polyps are generally
grouped in colonies connected by a coenenchyme, the ccelenteron of each polyp
communicating with that of the other members of the colony by means of basal
endodermal canals.

Family. ZOANTHIDiE, Dana, 1846.

(With the definition of the group. )

Sub-family. Beach ycnemin^e, n. s.-f.*

Zoanthese in which the sulcar element of the primitive sulco-lateral pair of
mesenteries (cnemes) is imperfect : —

GENERA AND TYPE SPECIES.

Zoanthus, Lamarck. Type Z. sociatus (Ellis).

Isaurus, Gray. ,, /. tuberculatus, Gray.

( ? Mammillifera, Lesueur. ,, M. auricula, Lesueur.)

Gemmaria, Duchassaing et Michelotti. ,, G. rusei, Duch. and Mich.

Palythoa, Lamouroux. ,, P. mammillosa (Ellis and Sol.).

Sphenopus, Steenstrup. ,, S. marsupialis, Steenstr.

* /Spaxvs, short ; /xa/cpos, long ; wr^r], a radius or spoke of a wheel. We have tried hard to discover a
short term for a mesentery, which would readily lend itself to combination with other words, but without

Haddon and Shackleton — A Revision of the British Actinia. 627

Sub-family. Mackocnemin^, n. s.-f.*

Zoanthese in which the sulcar element of the primitive sulco-lateral pair of
mesenteries (cnemes) is perfect : —

GENEEA AND TYPE SPECIES.

Epizoanthus, Gray. Type E. incrustatus (Dub. and Kor.).

Parazoanthus, n. g. ,, P. axinellce (Schmidt).

The Zoanthese constitute a very well-marked division of the Actiniae ; no
connecting forms between these and any other group are known.

The classification of the Zoanthese proposed by Erdmann has been adopted by all
subsequent writers ; and as his was the first which was based on internal anatomy,
we need not enter into a discussion of the earlier systems.

Erdmann adopts Andres' two families, the Zoanthidse and the Sphenopidse, with
the following definitions : — " Zoanthidse : Zoantheen, welche durch ein Ccenenchym
zu Colonien vereinigt werden ; " and "Sphenopidse: Einzellebende Zoantheen,
welche mit ihren abgerundeten Korperende im Sande stecken oder mit einer Art
Haftscheibe am Boden festsitzen." It is strange that these families should be
based solely upon the habit of growth. In the second family he places Sphenopus
and his " genus novum" ; the latter is undoubtedly the free (or Sidisia) variety of
an Epizoanthus. It is very probable that this is really the free- variety of the type
species of Epizoanthus (E. incrustatus). As this form passes out of the family we
see no reason for retaining a family for Sphenopus, especially as an isolated mode
of growth occurs in the other family, as McMurrich has shown that Gemmaria rusei
is "solitary, being attached topebbles without the development of any ccenenchyme "
(1889, p. 124), and the individuals of his G. isolata " were scattered and buried up to
the tentacles in the sand " (1889 a, p. 65) ; and it is characteristic of the genus
Isaurus for the polyps to be either solitary, or in small groups with a feeble
ccenenchyme. We therefore think it preferable to base divisional characters on
anatomical differences.

McMurrich has adopted Andres' three divisions, the third being the Bergidse.
As nothing is known about the structure of the latter we think it better to omit
them altogether.

success. The objection to the word " cneme " is that it has reference to the appearance of a transverse
section of an Actinian rather than to a mesentery as it actually exists. As the investigation of the
Zoantheae, at least, must principally he made by means of transverse sections, this objection has not much
weight.
* Ibid.

4 U 2

628 Haddon and Shackleton— A Revision of the British Actiniae.

We acknowledge only one family in the group which we divide into two
sub-families, the Brachycneminse, and the Macrocneminae, which are based upon
the two well-known types of mesenterial arrangement. It is worthy of notice that,
so far as our knowledge at present extends, the Macrocneminse alone are repre-
sented in the North Atlantic, although they are world-wide in distribution.

The following Table shows the chief generic distinctions at a glance, and
demonstrates that the group is a very homogeneous one. We regard Parazoanthus
as being the least specialised genus on account of its having a single endodermal
sphincter muscle, and Zoanthus as the most specialised, as it possesses a double
mesoglceal sphincter muscle. We omit Mammillifera, as the type species have
never been described from an anatomical point of view : —

Genus.

Mesenterial arrange-
ment.

Sphincter.

Gonads .

Body-wall and Coenenchyme.

7 An \-\ 4-1-1 ii q

U VaLl uli Uoi

1 ' L uil/li V L 11L llllO .

r)miViIp tYtpqficyl fpfl 1

U UU1C X±±KjOVJp~l\JCGvl i

o <->r o > ¥

+

Unincrusted ; well-deve-

1 C\Y\C±(\ an + r\n Drm q 1 nQtial
lUJL'L-U LI IUUL 1 Illctl CclUcH

, system.

Isaurus.

Brachycnemic.

Single mesoglceal.

<? or $, 2
+

Unincrusted ; ectodermal
and endodermal bays
and small canals ; some-
( times solitary.

Gemmaria.

Brachycnemic.

Single mesoglceal.

$, ¥

( Incrusted ; lacunae ; often
( solitary, always attached.

Palytboa.

Brachycnemic.

Single mesoglceal.

<?, $

[Similar to above, but
| P0lyPs immersed in
( expanded coenenchyme.

Sphenopus.

Brachycnemic.

Single mesoglceal.

?

f Incrusted ; cell-islets ; al-
t ways solitary and free.

Epizoanthus.

Macrocnemic.

Single mesoglceal.

<?, ¥

Incrusted ; cell-islets.

Parazoanthus.

Macro cnemic.

Endodermal.

<?. ?

Incrusted ; ectodermal
canals ; cell-islets ; en-
circling sinus ; ectoderm
always continuous.

Haddon and Shackleton — A Revision of the British Actinice.

629

In the following list we have enumerated immediately after the generic
description all the species which can be definitely referred to any species, adding
in brackets [ ] the initials of the zoologists who have investigated those forms,
and on whose authority the generic allocations are made. The initials are as
follows: — A., Andres; E., Erdmann ; E. & H., Erdmann and Hertwig, for those
species described in the Supplement to Hertwig's 11 Challenger" Report, 1888, the
anatomical work on the Zoantheae being done by Erdmann; H., Hertwig (1882);
H. & S., Haddon and Shackleton ; M., M°Murrich. Although other zoologists
have made anatomical investigations on some forms, yet in no other case is
there sufficient information given to enable one to determine the generic position
of a particular species.

In a few instances we have added those species which we think may safely be
regarded as probably belonging to a particular genus, e. g. Palythoa and those
species of Epizoanthus which form carcinaecia, owing to their having a similar
habit of growth to species whose genus is known. Beyond this we have not
dared to go, as enough confusion has been made in the group without our
gratuitously adding to it.

Family. ZOANTHIDiE.
Sub-family. B u a ch yc n e m i h m.

ZOANTHUS, Lamarck, 1801.

Brachycnemic Zoanthese, with a double mesoglceal sphincter muscle. The
body-wall is unincrusted ; the ectoderm is usually discontinuous ; well-developed
ectodermal canal system in the mesoglcea. Monoecious or dioecious. Polyps
connected by thin ccenenchyme.

EECOGNIZED SPECIES.

Z. sociatus (Ellis), 1767. — Dominica, Barbadoes, Guadeloupe, Bahamas, [M.].

Z. fios-marinus, Duch. & Mich., 1860. — St. Thomas, Bermudas, [M.].

Z. dance ( ?), of Hertw., 1888. — Bermudas (? if the same as Z. danai, Le Conte,

1851, Panama), [E. & H.].
Z. confertus, of Hertw., 1888. — Cape of Good Hope (?if the same as M. conferta,

Verrill, 1868, San Salvador, Acapulco), [E. & H.].
Z. coppingeri, Hadd. & Shackl., 1891. — Torres Straits, [H. & S.].
Z.jukesii, Hadd. & Shackl., 1891.— Torres Straits, [H. & S.].
Z. macgillivragi, Hadd. & Shackl., 1891. — Torres Straits, [H. & S.].
Z. sp. (?), Hertw., 1882.— Bermudas, [H.].

«

630 Haddon and Shackleton — A Revision of the British Actinice,

ISATJRUS, Gray, 1828.

Large brachycnemic Zoanthese, with a single mesoglceal sphincter muscle.
The body- wall is unincrusted ; the ectoderm is discontinuous ; ectodermal and
endodermal bays and small canals in the mesogloea. Monoecious or dioecious.
Polyps in small clusters or solitary.

RECOGNIZED SPECIES.

/. tuierculatus, Gray, 1828. — Guadeloupe, Bermudas, [M.].

/. spongiosis (Andres), 1877. — Port Natal, [A.].

1. asymmetricus, Hadd. & Shackl., 1891. — Torres Straits, [H. & S.].

PROBABLY BELONGING TO THIS GENUS.
/. cliftoni (Gmy), 1867.— W. Australia.

[?Mammillifera,* Lesueur, 1817.

M. auricula, Lesueur, 1817. — St. Vincent; Dominica.
M. nymphcea, Lesueur, 1817. — St. Christopher.]

GEMMARIA, Duchassaing et Michel otti, 1860.

Solitary brachycnemic Zoanthese, with a single sphincter mesoglceal muscle.
The body- wall is incrusted with particles of sand. The ectoderm is usually
discontinuous, but may be continuous. Lacunae and cell-islets are found in the
mesogloea. Dioecious.

RECOGNIZED SPECIES.

G. rusei, Duch. & Mich., I860.— St. Thomas, Bermudas, [M.].
G. isolata, MeMurr., 1889.— Bahamas, [M.].

G. macmurricki, Hadd. & Shackl., 1891. — Torres Straits, [H. & S.].
G. mutuki, Hadd. & Shackl., 1891. — Torres Straits, [H. & S.].

PROBABLY BELONGING TO THIS GENUS.
G. philippinensis (Gray), 1867. — Philippines.

* The position of this genus cannot be settled until the type species have been recovered and
sectionized.

Haddon and Shackleton — A Revision of the British Actinia. 631

PALYTHOA, Lamouroux, 1816.

Brachycnemic Zoantheae, with a single mesoglceal sphincter muscle. The body-
wall is incrusted; the mesogloea contains numerous lacunae, and occasionally
canals. Dioecious. Polyps immersed in a thick coenenchyme.

RECOGNIZED SPECIES.

P. mmnmillosa (Ellis & Sol.), 1786. — Jamaica, = Corticifera lutea of Hertwig,
1888. — Bermudas, probably not C. lutea, Quoy & Gaim.,
1833.— Tongatabou, [E. & H.J.

P. ocellata (Ellis & Sol.), 1786. — Dominica, Jamaica, [M.].

P. glareola (Lesueur), 1817. — Guadeloupe, Bermudas, [M.].

P. flava (Lesueur), 1817. — St. Thomas, Bahamas, [M.].

P. tuberculosa, of Hertwig, 1888. — Cape of Good Hope; probably not

P. tuberculosa, Klunz., 1877. — Red Sea, [E. & H.].
P. howesii, Hadd. & Shackl., 1891.— Torres Straits, [H. & S.].
P. kochii, Hadd. & Shackl., 1891.— Torres Straits, [H. & S.].
P. ccesia?, Dana {fide H. & S., 1891).— Torres Straits, [H. & S.].

THE FOLLOWING PROBABLY BELONG TO THIS GENUS:—

P. aggregata (Lesson.), 1830. — Society Archipelago.
P. lutea (Quoy & Gaim.), 1833. — Tongatabou.
P. flavo-viridis, Ehr., 1834. — Red Sea.
P. argus, Ehr., 1834. — Red Sea.
P. ccesia, Dana, 1846. — Fiji.

P. glutinosa, Duch. & Mich., 1866. — St. Thomas, probably = P. ocellata,
(E. & S.).

P. caribceorum, Duch. & Mich., 1866. — St. Thomas.
P. cinerea, Duch. & Mich., 1866. — St. Thomas.

P. tuberculosa, Klunz., 1877. — Red Sea. Probably neither of Hertwig nor

of Studer, 1878.— New Ireland.
P. calcaria, Mull., 1883.

632

Haddon and Shackleton — A Revision of the British Actinice.

SPHENOPUS, Steenstrup, 1856.

Free solitary brachycnemic Zoanthese, with a single, very long mesoglceal
sphincter muscle. The body-wall is incrusted. Cell-islets are present in the
mesoglcea.

RECOGNIZED SPECIES.

S. marsupialis, Steenstr., 1856. — Tranquebar, Pulo Faya, China Seas, Gray ;

(? Madras, H. & S.), [H. & S.l.
S. marsupialis, var. bursiformis, Gray, 1867. — Massachusetts Bay, N. America.

(This requires confirmation.)
S. arenaceus, Hertw., 1882. — Cape York, [H.].
S. pedunculatus, Hertw., 1888. — Philippine Islands, [E. & H.].

Sub-family. Macrocnemin^.

EPIZOANTHUS, Gray, 1867.

Macrocnemic Zoanthese, with a single mesoglceal sphincter muscle. The
body-wall is incrusted. The ectoderm is usually continuous, but may be discon-
tinuous ; cell-islets in the mesogloea. Dioecious polyps, connected by coenenchyme,
which may be band-like, incrusting, or greatly reduced, as in the free forms.

RECOGNIZED SPECIES.

E. incrustatus (Dub. & Kor.), 1847. — Norway, [H. & S.], = E. papillosus
(Johnst.), 1842. — W. coast of Britain, [H. & S.], = Sidisia
barkei, Gray, 1858 (free variety). — Shetlands, [H. & S.],
= E. americanus, Verr., 1864 (and free variety). — E. coast of
N. America, [H. & S.], = E. cancrisocius of Hertw. (not of
Studer), 1888.— Nova Scotia, [E. & H.].

E. arenaceus (D. Ch.), 1836. — Mediterranean, (~H. & S.].

E. couchii (Johnst.), 1838.— S. W. Britain, [H. & S.].

E. norvegicus (Kor. & Dan.), 1877. — Norway, [H. & S.].

Haddon and Shackleton — A Revision of the British Actinice. 633

E. paguriphilus, Verr., 1882. — E. coast of N. America; W. coast of France;

W. coast of Ireland, [H. & S.].
E. parasiticus, of Hertw., 1882. — Japan (probably not of Verrill, 1862), [H.].
E. thalamophilus, Hertw., 1888. — Valparaiso, [E. & H.].
E. stellaris, Hertw., 1888. — Philippines, [E. & H.].
E. elongates, Hertw., 1888.— Monte Video, [E. & H.].
E. erdmanni (Dan.), 1890. — N. coast of Norway ; Spitzbergen, [H. & S.].
E. macintoshi, n. sp. — Shetlands, [H. & S.].
E. wrightii, n. sp. — Dublin Bay, [H. & S.].

PROBABLY BELONGING TO THIS SPECIES.

E. cancrisocius (Martens), 1875, ? of Studer, 1878. — Japan.
E. parasiticus, Verr., 1864. — E. coast of N. America.
E. abyssorum, Verr., 1885. — E. coast of N. America.
E. eupaguri (Mar.), 1882.

PARAZOANTHUS, n. g.

Macrocnemic Zoanthese with a diffuse endodermal sphincter muscle. The
body-wall is incrusted ; the ectoderm is always continuous ; the mesoglcea contains
ectodermal canals, cell-islets, and an encircling sinus. Dioecious.

RECOGNIZED SPECIES.

P. axinellce (Schmidt), 1862. — Mediterranean, [E.], [H. & S.].

P. anguicoma (Norm.), 1868. — Shetlands; W. Britain, [H. & S.].

P. dizoni, n. sp. — W. of Ireland, [H. & S.].

P. dichroicus, H. & S. 1891.— Torres Straits, [H. & S.J.

P. douglasi, H. & S., 1891.— Torres Straits, [H. & S.].

P. (sp.)? (Hertw.), 1888.— Tristan d'Acunha, [E. & H.].

P. hertwigi, n. n. — Tristan d'Acunha, [E. & H.], name proposed by us (see
p. 616) for P. anguicoma, of Hertwig, 1888.

TKANS. Kor. DUB. SOC, N.S. VOL. IV., PAKT XII.

634

Haddon and Shackleton — A Revision of the British Actinias.

SYSTEMATIC ACCOUNT OF THE BRITISH ZOANTHEjE.

ZOANTHIDiE.

I. Brachycnemiisle. (None British.)
II. Macrocnemin^e.

EPIZOANTHUS, Gray, 1867.

Spongia (pars), Johnston, 1834. Sidisia, Gray, 1858.

Dysidea ? (pars), Johnston, 1842. Carolia, Gray, 1867.

Mammillifera (pars), Auct. Polythoa (pars), Andres, 1884.

Zoanthus (pars), Auct. Palythoa (pars), Cams, 1884.

Macrocnemic Zoanthese, with a single inesoglceal sphincter muscle. The body-
wall is. incrusted ; the ectoderm is usually continuous, but may be discontinuous;
cell-islets in the mesoglcea. Dioecious. Polyps connected by coenenchyme, which
may be band-like, incrusting, or greatly reduced as in the free forms.

The genus Epizoanthus was established by Gray in 1867 for incrusted Zoanthese :
" II. coral attached ; cells arising from a foliaceous expanded base. . . . The base
expanded foliaceous (parasitic on shells) ; the cells cylindrical, simple, separate
from each other from the base ; tentacles numerous " (p. 237). E. papillosus, Johnst.,
is his type. Verrill adopted Gray's genus. At first Hertwig (1882) agreed with
Verrill in using this term to denote incrusted forms which rose above their
coenenchyme. After Erdmann's investigations, he (1888) restricted the genus to
macrocnemic Zoanthese, with "Integument incrusted, coenenchyme (mostly?)
lamellar ; sphincter simple, mesogloeal ; mesenteries arranged on the macrotype ;
colonies (mainly ?) parasitic " (p. 37). We have studied the type species of this
genus, and find that it does conform to Erdmann's and Hertwig's definition of the
genus. We may add that all observers have agreed in relegating to this genus all
those incrusted Zoanthese which form carcinaecia.

In 1858 Gray erected the genus Sidisia for free Zoanthese, " which may be
characterized by the emission of buds on the surface of the cylindrical body "
(p. 532), 8. barleei being the sole species. He considered that this species
"evidently belongs to quite a different group" from Dysidea papillosa, Johnst.,
which Mr. Barlee (in Utt.) informed Gray "was a Zoanthus, allied to the genus
Mammillifera of Lesueur," an opinion which Gray adopted.

Our investigations prove that S. barleei is only a variety of E. incrustatus (= E.
papillosus). We do not propose to keep the name Sidisia for the genus, although it
has priority, and for this reason : it was solely erected for a species which is only

Haddon and Shackleton — A Revision of the British Actinia'.

635

a variety of an older form ; and the name has only been occasionally retained for
this variety of that particular species, whilst Epizoanthus has been universally
adopted for the more typical forms of this genus. Both names were originated
by Gray, and we have therefore less hesitation in keeping to the latter.

Erdmann examined some free Zoan these which were dredged by " H. M. S.
' Triton,' 640 Fuss " (1885, p. 481). Without paying any attention to the litera-
ture of the subject, he relegated these to a new genus, which he did not name.
Very likely it is the Shetland species. Danielssen (1890) described specimens which
he referred to Erdmann's new genus, which he named Mardcell ; and he called his
new species M. erdmanni (p. 117). Through the courtesy of Dr. Danielssen we
have been able to examine this form, and have cut sections of it. We are perfectly
satisfied as to its specific distinction from the free variety of E. incrustatus.

The imperfect mesenteries of E. erdmanni are much more developed than in E.
incrustatus ; and there is almost invariably a well-marked lacuna in the mesoglcea at
the base of the insertion of each mesentery.

In every respect it is an Epizoanthus, the sphincter being mesogloeal instead of
endodermal, as Danielssen states, and the arrangement of the mesenteries is
macrocnemic, though Danielssen's figures do not show this.

BEITISH SPECIES OF THE GENUS EPIZOANTHUS.

E. incrustatus, Diib. & Kor., 1847.
E. couchii, Johnst., 1838.
(E. rubricornis, Holdsw., 1861.)

E. paguriphilus, Verr., 1882.
E. macintoshi, n. sp.
E. wrightii, n. sp.

Forming carcinfecia,

Free olonies,

SYNOPSIS OF BEITISH SPECIES OF EPIZOANTHUS.

One polyp ventral, remainder marginal, . . . E. paguriphilus.

Polyps on upper surface only,

Polyps radiating in one plane from a common
point ; diameter to height of polyp as 1 to 2,

E. incrustatus.

Polyps radiating in all directions from a common )

J 1 & } (E. rubricornis.)

point ; diameter to height of polyp as 1 to 4, . >

'a. Ccenenchyme usually band-like, ) E. couchii.

Diameter to height of polyp as 1 to 4, . . . [ (S. W. Ireland.)

„ as 1 to 3, . . J (S- W. England.)

Incrusting Colonies, . <

Coenenchyme probably band-like ; diameter of
polyp nearly as great as height,

E. macintoshi.

b. Coenenchyme irregular ; diameter of polyp greater \ wrightii
\ than height J

The above relative proportions of diameter to height refers solely to contracted
spirit specimens. 4X2

636 Haddon and Shackleton — A Revision of the British Actinice.

Epizoanthus incrustatus (Diib. and Kor.).
(PI. lviil, figs. 1-22; PI. lix., fig. 2; PI. lx., fig. ].)

Spongia suleria :

Johnston, 1834, Loudon's Mag. Nat. Hist., vn., p. 431, fig. 60.

Dysidea ( ?) papillose/ :

Johnston, 1842, Hist. Brit. Sponges, pp. 190, 251 (in part), fig. 18 (not pi. xvi., figs. 6, 7),
Gray, 1858, Proc. Zool. Boo., p. 531.

Mammillifera incrustata :

Diiben and Koren, 1847, Forhandl. Skand. Naturf. Mode, p. 268 (cf. transl. in Isis, 1848,
p. 536). Sars, 1851, Eeise i Lofot. og Finm., Nyt Mag. Naturvid., vi. (2), p. 142. Danielssen,
1859, Nyt Mag. Naturvid., xi. (1861), p. 45.

Sidisia barleei :

Gray, 1858, Proc. Zool. Soc, xxvi., p. 532, pi. x., fig. 8. Gray, 1867, Proc. Zool. Soc,
p. 237. Norman, 1868, Rep. Brit. Assoc. Adv. Sci., p. 319.

Zoanthus couchii :

(Not of Couch). Landsborough (in part), 1852, Brit. Zooph., p. 225. Holdsworth (in part),
1858, Proc. Zool. Soc, p. 557, pi. x., fig. 3 ; and 1859, Ann. Mag. Nat. Hist., (3), nr., p. 152.
Var. diffusa, Gosse, 1860, Brit. Sea Anemones, p. 298, pi. rx., fig. 10; and var. liher, p. 298,
pi. rx., fig. 9. Var. M. incrustata, Alder, Trans. Tyneside Nat. Field Club, v.

Zoanthus incrustatus :

Sars, 1860, Forhandl. Vidensk., Christiania, p. 141 ; also Forhandl. Skand. Naturf. Mode.
Kjob., vni., p. 691. Norman, 1868, Rep. Brit. Assoc. Adv. Sci., p. 319.

Epizoanthus americanus :

Verrill, 1864, Mem. Boston Soc. Nat. Hist., i., pp. 34, 45 (addenda); 1866, Proc.
Boston Soc. Nat. Hist., x., p. 335 (Gemmaria americana, Verrill, Am. Nat., n., p. 9, fig. 42) ;
1871, Am. Jour. Sci., n., p. 361. Dana, 1872, Corals and Coral Islands (2nd ed.), p. 62,
figs. 1, 2. Verrill, 1873, U. S. Fish. Com. Rep., pp. 446, 510, pi. xxxvm., figs. 286, 287 ; 1874,
Am. Jour. Sci., vn., p. 413 ; ibid. (3), xxrn., 1882, p. 316. Smith and Harger, 1874, Trans.
Connect. Acad., in., pp. 9, 10, 11, 55, pi. vm., fig. 2. Verrill, 1883, Bull. Mus. Comp. Zool.,
xi., 1883-1885, p. 60, pi. vm., figs. 1, 6 ; 1885, U. S. Fish. Com. Rep. (1883), p. 534.

Epizoanthus papillosum :

Gray, 1867, Proc. Zool. Soc, 1867, p, 237. Ridley, 1886, Proc. Roy. Irish Acad. (2), rv.,
No. 5, Sci., p. 617.

Pah/thoa arenacea :

Cams, 1884 (not of D. Ch.), Prod. Faunaa Medit., p. 75.

Polythoa arenacea :

Andres, 1884 (not of D. Ch.), Le Attinie, p. 308. Pennington, 1885, Brit. Zooph., p. 182.

Epizoanthus cancrisocius :

Hertwig (not of Studer), 1888, Zool. Voy. " Challenger," Rep. Actiniaria, Suppl. lxxiii.
p. 41, pi. i., fig. 15.

Polythoa incrustata :

Bourne, 1890, Journ. Marine Biol. Assoc, i., p. 319.

Haddon and Shackleton — A Revision of the British Actiniae.

637

Form. — Thickly incrusted forms, of which the well- grown polyps are twice as
high as broad. Two well-marked varieties: — A. Incrusting form, coenenchyme
forming carcinsecia by replacement of a gasteropod shell ; the two primary polyps
at each end of the shell, usually forming a well-marked posterior marginal row of
polyps ; other polyps scattered on dorsal surface ; maximum number about 10—12,
varying much in height ; no polyps on the under surface of the carcinsecium.
B. Free form, primarily consisting of two individuals base to base, each of which
may divide more or less regularly, or one only may divide.

Colour. — Sandy.

Dimensions. — Polyps, 3— 9 mm. in height; l'5-4'5 mm. in average diameter.
Colonies, greatest length, 22— 35 mm. ; greatest breadth, 13— 20 mm.

Locality. — Shetlands ; W. and S. W. Ireland ; N. E. England ; Lerwick
(Barlee); 30 miles E. and N. of Brassey I., 70—80 faths. (Barlee) ; Haaf, Shetland,
1863 (A. M. N.); 5-8 miles E. of Balta, Shetland, 40-50 faths., July 20-23,
1867 (A. M. N.), "commensal with Pagurus Icevis " (PI. lviii., figs. 1—13);
also in St. Magnus Bay (A. M. N.); 40 miles S. W. of Cape Clear, Co. Cork,
80—90 faths., 1885, commensal with Enpagurns excavatus and Spiropagurus Icevis
(A. C. H.); Nymph Bank, Co. Cork, 50 faths., 1886 (A. C. H.); Clew Bay, 1890;
33-40 faths. off Aran, Co. Galway, 1891 (A. C. H.), (PI. lviii., figs. 14-22);
33—36, Donegal Bay, 1891 (A. C. H.); Scarborough (Bean, /. Johnston);
Northumberland, "deep water" (Alder) ; 48° 59' 42" N., 10° T 27" W., 90 faths.,
1889 (G. C. Bourne), associated with E. meticulosus ; Plymouth Sound (specimens
in Mus. of Marine Biol. Assoc. Laboratory).

The geographical distribution of this species is North Atlantic, extending from
the east coast of N. America to N. W. Europe.

The synonymy of this species is much involved, but we think the foregoing
list is sufficiently complete. We agree with Norman in rejecting Johnston's
specific name, as he considered it to be a sponge ; and some years later (Hist. Brit.
Zooph., 2nd ed., 1847, p. 202) he quotes Couch's description of Z. couchii, and has
" the pleasure of naming this the only European Zoanthus after its discoverer."
It is therefore clear that he did not regard his own form as a Zoanthean. We are
thus obliged to adopt the specific name given to this species by Diiben and Koren.
Holdsworth, Gosse, and others have regarded this as a variety of E. couchii: we
think that it will be admitted from our anatomical studies that this is not the
case ; neither can it be associated with E. arenaceus, D. Ch.

Owing to the kindness of Canon Norman we have been enabled to study some
authentic Norwegian specimens of this species, and find them to be identical with
the Shetland and Irish forms.

Dr. Gray had no hesitation in referring some specimens from the coast of
Massachusetts, collected in forty-fathom water (Proc. Zool. Soc, 1867, p. 237), to

638 Haddon and Shackleton — A Revision of the British Actiniae.

this species. Verrill, however, erected a new species for the forms dredged oil the
east coast of N. America. Thanks again to Canon Norman's courtesy we have
examined some of Professor Verrill's specimens, and we must confess to not being
able to distinguish them specifically from the European examples. It is difficult
to understand why Professor Hertwig ignored these two specific names and
adopted for his specimen (Challenger Sta., 49, off Nova Scotia, 85 faths.) the
name of a form from the Pacific Ocean. Verrill (1885) says it (incrusting variety)
ranges from " 49-906 fathoms; abundant."

The synonymy has also been complicated on account of the occasional
free habit. This variety was first named Sidisia barleei by Gray. Gosse,
Holdsworth, and others have regarded it simply as a variety of the typically
incrusting Z. couchii. Verrill, too, recognises a free and an incrusting variety
of E. americanus, and also for his E. abyssorum ; of this latter he says : ' ' This
species generally forms the carcinsecia of Parapagurus piloswianus, but sometimes
consists of two or three large obconic polyps arising from a grain of sand"
(I. c. 1885, p. 535).

Norman, however, in referring to this variety, says (1868, p. 319): "Taken
abundantly in company with Zoanthus incmstatus, of which I was at one time
inclined to consider it a variety ; but more careful examination and dissection has
convinced me that there are certain distinctions between the two, besides the fact
of Sidisia being a free-living, unattached form. Whether these distinctions are
specific or sexual, a careful examination of the living animal must hereafter
determine." We have compared microscopically the two varieties, and find them
to be essentially similar.

Incrusting Form. — Ccenenchyme incrusting gasteropod shells inhabited by
hermit-crabs, the shells being rapidly absorbed and rejDlaced by the ccenenchyme
which thus forms the carcinsecium. In old specimens the polyps appear to be
irregularly arranged ; but on an examination of younger specimens, three series of
polyps can be distinguished. In the youngest example we have seen (PL lviil,
fig. 14) there is only a single polyp, which is situated at the apex of a small
gasteropod shell, the shell itself being entirely coated by the ccenenchyme'
The second polyp arises at the oral axis, or hilum, of the shell (fig. 15).
A third one usually makes its appearance above the mouth of the shell.
We have seen several cases in which the apical polyp is in the act of
fission (PI. lviii., fig. 12). These three polyps form the first series. The second
series forms a marginal row which corresponds to the aboral varex of such a shell
as Ranella. The third series forms an irregular row between the two former. In
no specimen of the very large number we have examined is there a polyp on the
under surface of the carcinsecium. The polyps bend slightly towards the oral or
anterior aspect of the carcinseciuin. In a contracted state the capitulum forms a

Haddon and Shackleton — A Revision of the British Actinice. 639

flattened disc-like termination to the polyp, on which indistinct radii, usually
about 18 or 20 in number, can usually be discerned. The disc-like termination is
sensibly of greater diameter than the column of the polyp.

Free Form. — The earliest stage we have seen consists of two polyps base to
base. These may divide by fission more or less symmetrically (PI. lviii., figs. 5-11),
or one polyp may divide repeatedly, and the other not at all (PI. lviii., fig. 2—4).
The variations are so great that it would be impossible to attempt to describe
them all ; and we would here point out that the two species of Epizoanthus we
have examined which have free forms (viz. E. incrustatus, E. erdmanni) vary in
such a similar manner that the variations appear to have no taxonomic value ; the
same also holds good for E. abyssorum, Verr. We have seen specimens of
similar varieties of other species which have not as yet been identified ; one which
comes from Naples will, we believe, be found to be a free variety of E. arenaceus.
The size of the polyps and the character of the incrustations seem to be the only
external features which distinguish the free forms of these species from each other,
and these are obviously insufficient.

It is worthy of notice that the capitulum of the free varieties is usually less
flattened than that of the incrusting forms.

The size which the polyps may attain apparently varies with the locality ; for
example, the largest of the Shetland specimens are 9 mm. in height, by 4*5 mm.
in diameter ; the largest colony from Balta measuring 30 x 20 mm. ; that from
Haaf being 35 x 20 mm. In the free variety the fully grown polyps average
6-7 mm. high, and 3— 3 5 mm. across ; the larger colonies being 22—23 mm. long
by 8—11 mm. broad. From the S. W. of Ireland, the polyps range up to 7*5 mm.
high by 3 \5 in diameter, the carcinsecia being 24 x 15 mm. The W. of Ireland
specimens from off Aran and from Donegal Bay run a good deal smaller : the
polyps average 3—6 mm. in height and 1*5—3 mm. in diameter; most of the
colonies are quite small, the largest being 22 x 13 mm. The nature of the
incrustations also gives them a black-gray colour. The difference in size and
colour between these and more normal specimens is so marked as to constitute a
distinct variety.

Verrill's original description (1866, p. 34) of this species (his Epizoanthus
americanus, n. sp.) is as follows: — " This species, which is parasitic on shells, has
an incrusting base, smooth and uniform on the lower side of the shell, but giving
rise to from fifteen to twenty polyps on the upper side, which diverge in all
directions. Polyps variable in height and size, those of the upper central portion
generally half an inch in height (13 mm.) and one-eighth (3'25 mm.) in diameter;
while those around the margin of the base are not more than half so large, and
much crowded. Base spreading over and completely investing dead shells of
Natica, Buccinum, &c, both externally and internally. The substance of the

640

Haddon and Shackleton — A Revision of the British Actinia'.

shell in every case has been entirely removed, but the form in all parts is perfectly
preserved by the membranes of the polyps, while the cavity is inhabited by a
species of hermit crab (Eupagurus pubescens). Column pillar-like, smallest in the
middle, increasing gradually below, but enlarging rapidly at the summit. Walls
thin, covered by a layer of closely adhering fine sand. When contracted, the
summit is slightly concave ; and in the medium-sized polyps has seventeen, in
the largest twenty -four sulcations, radiating from the centre, which is seldom
completely closed. Tentacles, forty-eight or more, short, conical.

The localities at which this species had been obtained up to that time are
given by Verrill in 1882, p. 316. The free or type-form (of E. americanus, Verr.)
occurred at 28 stations, 28 to 487 fathoms, whereas the incrusting variety
"(= Zoanthus norvegicus, Kor. & Dan.)" occurred at 11 stations, 69-160 fathoms.
The former is by far the most abundant numerically. Later (1885), he gives the
bathymetrical range of the free form as " 26— 547 fathoms ; generally diffused
and very abundant" (p. 534); and of the incrusting variety, " 49— 906 fathoms;
abundant" (p. 535).

Smith and Harger (1874) report this species from off the coasts of New Jersey
to the Gulf of St. Lawrence ; the specimens with incrusted shells inhabited by
Eupagurus pubescens came from 60—65 fathoms ; while those from 430 fathoms
were on stones and on hydroid stems. The figure, which is of a magnified polyp,
is of no real value.

In Verrill' s last Paper (1885, p. 60), he says it is mostly commensal with
Eupagurus politus, Smith, and E. /crogeri, very common ; those on grains of sand
(free variety) were even more abundant. Some occurred incrusting sponges,
shells, hydroids, tunicates, gorgonia, Paramuricea grandis, pebbles, &c. The
original specimens off New Jersey, 30 fathoms, were commensal with E. pubescens.
We think it possible that more than one species has been identified by our
American colleague as E. americanus.

Bodg-wall (PI. lix., fig. 2). — The incrustations in this species are numerous,
and consist for the most part of coarse grains of sand, so that it is difficult to
make out the structure of the body-wall from our sections. The ectoderm is
continuous, and is covered by a cuticle, to which diatoms and dark granules are
attached. Nematocysts, -containing similar granules, are usually abundant in
the ectoderm. The incrustations are embedded in the mesoglcea throughout its
entire thickness, often protruding into the ccelenteron. Single cells are oc-
casionally found enclosed in the mesoglcea ; and lacunae are sometimes found
near the union of the mesenteries with the body-wall ; but the mesoglcea is for
the most part devoid of cell enclosures. The usual endodermal muscular layer
is present, being especially well-developed in the upper part of the column. The
endoderm is formed by a thin layer of columnar cells of uniform height.

Haddon and Shackleton — A Revision of the British Actinice.

641

Sphincter muscle. — The mesogloeal sphincter muscle is short, and consists of
well-defined cavities.

Disc and Tentacles. — The disc and tentacles present the usual structure. The
muscular layers appear to be feebly developed.

(Esophagus. — The shape of the oesophagus in cross-section varies in our speci-
mens. Sometimes it is almost circular (PI. lx., fig. 1), the groove forming a
very slight depression ; in other specimens the groove is fairly-well marked.
The ectoderm is almost smooth, being but very slightly folded.

Mesenteries. — The arrangement of the mesenteries is macrocnemic. The
imperfect mesenteries are very slightly developed, extending into the coelenteron
but little beyond the endoderm. The ectoderm of the oesophagus is reflected, and
forming a series of folds along each mesentery, is continued downwards in the
usual manner to form the mesenterial filaments. The mesogloea of the mesenteries
is slightly developed. The muscle-fibres form simple layers, there being no
mesogloeal plaitings. The endoderm of the mesenteries is thin, resembling that
of the body- wall.

Gonads. — There were no gonads in the specimens examined by us.

Var. barleei. — The specimens we have cut of the free variety agree very closely
in their anatomy with the above account ; but the sphincter muscle appears to be
longer and more powerful.

Epizoanthus paguriphilus.
(PI. lviii., figs. 23-25 ; PI. lix., fig. 6 ; PI. lx., fig. 5.)

Epizoanthus paguriphilus :

Verrill, 1882, Am. Journ. Sci. (3), xxm., pp. 137, 316; 1883, Bull. Mus. Comp. Zool.,
Cambridge, Mass., xi. (1883-85), p. 61, pi. vin., fig. 5 ; 1884, Am. Fish. Com. Rep. for 1882,
p. 658; 1885, Am. Fish. Com. Rep. for 1883, p. 535, pi. vm., fig. 28. Bourne, 1890, Journ.
Marine Biol. Assoc., i., p. 318.

Zoanthus (Corticanthus) paguriphilus :

Andres, 1884, Le Attinie, p. 326.

Form. — Colonies always forming carcinsecia; slightly i n crusted ; mesogloea
very thick ; one polyp on ventral surface, the remainder forming a radiating
single row, the " posterior polyp " of which is the smallest.

Colour. — Brownish in spirit specimens, but bluish-gray in colour where the
thin incrustation is rubbed away.

Dimensions. — Average diameter of coenenchyme, 55 mm. ; average height of
polyps, 20-25 mm. ; average width of polyps, 12—16 mm. ; average thickness of
polyps, 8—10 mm.

TEANS. EOT. DUB. SOC, N.S. VOL. IV., PART XII. 4 Y

642 Haddon and Shackleton — A Revision of the British Actinice.

Locality.— W. and S. W. Ireland: — 50° 29' 26" N., 11° 4' W., 400 faths., July
11, 1889 (G-. C. Bourne): 500 faths., 54 miles off Achill Head, Co. Mayo,
July 10, 1890 (A. C. H.), (PI. lviii., fig. 25). The specimens figured on PI. lviii.,
figs. 23, 24, are in the British Museum; they came from 71 miles W. by S. of
the Fastnet, 315 faths., and possibly also from deeper water [cf. Ann. Mag. Nat.
Hist. (6), iv., 1889, pp. 411, 430).

The geographical distribution of this species is North Atlantic, extending from
the N. E. coast of America to N. W. Europe, in deep water.

This is the largest and most striking of the species of British Zoanthese, and is
quite a recent addition to our fauna.

The polyps are in two positions, one central and inferior, the remainder
marginal, divergent, and uniserial. The ccenenchyme entirely surrounds the
shell on which it grows, save for the orifice through which the commensal hermit-
crab emerges. The orifice is ventrally situated, and is about 5 mm. distant from
the anterior border of the carcinsecium, and is from about 15-20 mm. in diameter.

Immediately behind the orifice is a polyp, which in spirit-specimens does not
rise above the general surface of the ccenenchyme, and is less than 10 mm. in
diameter.

The marginal polyps are prominent, and elliptical in section. At the
posterior end of the carcinsecium one polyp can readily be distinguished as being
markedly smaller (15mm. in height) than the other marginal polyps; this we
term the " posterior polyp." There are in the three specimens which we have
examined four well-grown polyps to the left of the posterior polyp, and four, five,
and six, respectively, on the right side of the carcinsecium.

There is a space of 20 mm. between the right and left polyps on the anterior
convex border of the carcinsecium. Under-surface of the carcinsecium flat ; upper
surface irregularly convex, with the greatest prominence towards the right.

A young specimen, which one of us dredged off the W. of Ireland, and which
is drawn of the natural size in PI. lviii., fig. 25, shows that the order of
the appearance of the polyps is probably as follows: — (1) the ventral polyp;
(2) the posterior polyp ; (3) the right and left anterior polyps ; (4) the succeeding
lateral polyps, of which the most posterior are the youngest. After four pairs of
marginal polyps have appeared the further production of polyps appears to be
confined to the right side.

This species is always commensal with Eupagurus pilosimanus.

Verrill first described this species in 1882 in the following terms : — " Polyps
few and very large, stout, with broad, swollen bases, arising from a very thick,
smooth, lubricous, gray or mud-coloured, translucent coenenchyme, which at first
invests small univalve shells, occupied by Parapagurus pilosimanus, but finally
grows far larger than the shell, and eventually absorbs it. Disc broad, larger

Haddon and Shackleton — A Revision of the British Actiniae. 643

than column ; tentacles numerous, rather long, light orange. Breadth of colony,
2 to 3 inches ; height of polyps in expansion, 1 inch or more ; diameter,
•5 to '7 of an inch" (p. 137). He further adds: — "Hitherto it has not been
found elsewhere than upon the back of this particular species of crab, which,
likewise, has not been found without its polyp. Of these associated creatures we
took about 400 couples, at station 947, in 312 fathoms, at one haul. It had
previously only been known by a few specimens taken by the Gloucester halibut
fishermen, in deep water, off Nova Scotia, and by ourselves in 1880." On p. 316
of same journal (Am. Jour. Sci. (3), xxiii.) he adds : — " [Station 947, S. by W. £ W,
89 miles off Martha's Vineyard, sand, mud, Aug. 9, 1881 ; temperature 44° Fr.
U. S. Fish. Com. Rep. for 1882-1884, p. 643]." " Epizoanthus paguriphila, Verrill,
sp. nov., 252-458 faths." — and gives a list of the stations at which it was
obtained.

In the Bulletin Mus. Comp. Zool. Cambridge, Mass., Verrill gives the colour
as translucent bluish or purplish-gray, or grayish-brown. In fresh specimens the
tentacles are pale- orange or salmon, with lighter tips, and polyps more or less of
a salmon-colour. The diameter of ordinary specimens, 60—70 mm. ; vertical
thickness, 25—30 mm. ; length of polyps, 1 5-20 mm. ; diameter in middle,
10-12 mm. ; and at base, 12— 18 mm. Some specimens considerably larger than
this were obtained. There are seven to twelve polyps.

Body-wall (PI. lix, fig. 6). — The ectoderm is not continuous, but is
penetrated by strands of mesoglcea, which unite (as in Z. coppingeri and other
species of Zoanthus and of Isaurus, and also in G. macmurrichi, to form a
peripheral layer of mesogloea. This peripheral layer of mesoglcea is not
distinguishable from the cuticle which covers the body. A more deeply stained
outer layer may often be seen, but it appears to be simply due to the shrinking of
the edge of mesoglcea under the action of heat. The columnar cells of the
ectoderm are closely packed, and stain deeply. They often contain dark pigment
granules. Nematocysts filled with similar pigment-granules are frequently found
amongst them. The few foreign particles (chiefly foraminifera and grains of
sand) which incrust this species are generally found partly embedded in the
ectoderm and partly in the adjacent mesoglcea. The mesoglcea is remarkably
thick, being relatively much thicker than in any other species of Zoanthean
examined by us. In section the mesogloea appears to enclose numerous " cell-
islets." Some of these, however, are much elongated, and might possibly be
regarded as forming parts of canals. We have not been able, however, to trace
any distinct canals arising from either ectoderm or endoderm ; and it seems more
probable that all these cell enclosures are completely surrounded by mesogloea.
The usual spindle-shaped cells drawn out into long fibres can be discerned
running through the mesoglcea. The endodermal muscular layer is not very well

644 Haddon and Shackleton — A Revision of the British Actinias.

developed ; the fibres are supported on slight, rounded plaitings of mesogloea.
The endoderm consists of a single layer of columnar cells, the peripheral portion
of the cells being of a deep brown colour owing to the presence of pigment-
granules.

Sphincter muscle. — The single mesoglceal sphincter is not a very powerful
one. No cavities are visible, the fibres being completely embedded in the
substance of the mesogloea.

Tentacles. — The ectoderm of the tentacles is thrown into transverse folds.
Numerous pigment-granules are to be found amongst the usual small nematocysts,
and the nuclei in the peripheral portion. The muscular layer is not well
developed. The mesogloea forms an extremely thin layer. The endoderm is also
pigmented.

Disc. — The disc is very similar in structure to the tentacles.

(Esophagus. — The ectoderm of the oesophagus is thrown into numerous folds.
There is a well-marked groove. The mesogloea forms a thin layer, except in the
region of the groove where it is somewhat thicker. It contains a few cell-islets.

Mesenteries. — The mesenteries have the usual macrocnemic arrangement.
The reflected ectoderm of the oesophagus is attached to them in the lower part
of the oesophageal region and lower down forms the filaments as in other
Zoantheae. The mesogloea is well developed in the oesophageal region, and here,
on one side of each mesentery, plaitings which support the longitudinal fibres can
be distinctly seen. Plaitings on both sides of the mesentery nearer to the body-
wall which support the parieto-basilar fibres are exceedingly slight. The mesogloea
is much thinner in the lower part of the body. The endoderm is very similar to
that which lines the body-wall.

Gonads. — The sexes are distinct. Male gonads are present in our sections ;
they are very numerous, and closely packed together, almost entirely filling up the
body-cavity below the oesophagus (PI. lx., fig. 5).

Epizoanthus couchii (Johnston).
(PI. lviil, figs. 26-28 ; PI. lix., fig. 4 ; PI. lx., fig. 3.)

Zoanthus couchii :

Johnston, 1838, in Couch, Cornish Fauna, in., p. 73, pi. xv., fig. 3 (not of Thompson, 1843,
Br. Assoc. Eep., p. 284 ; nor of Thompson, 1844, Ann. Mag. Nat. Hist., xni., p. 440; nor of
Landsborough, 1845, ibid., xv., p. 327; all of which are Sarcodictyon catena, cf. Johnston, 1847,
I.e., p. 180). Forbes, 1844, Ann. Mag. Nat. Hist., xrv., p. 415. Johnston, 1847, Brit. Zooph.,
ed. 2, p. 202, pi. xxv., fig. 9. Landsborough, 1852 (in part), Brit. Zooph., p. 225. Thompson,
1856, Nat. Hist. Ireland, rv., p. 462; Holdsworth, 1858 (in part), Proc. Zool. Soc, p. 557,
pi. x., figs. 4-7. Wright and Greene, 1858, Brit. Assoc. Eep., p. 180. Gosse, 1860, var. linearis,
Brit. Sea Anem., p. 297, pi. x., fig. 5. Hincks, 1861, Ann. Mag. Nat. Hist. (3), vra., p. 363.

Haddon and Shackleton — A Revision of the British Actinias.

645

(Dysirlea (?) papillosa :

Johnston, 1844, Hist. Brit. Sponges (in part), pp. 190, 251, pi. xvi., figs. 6, 7.

Carolia couchii :

Gray, 1867, Proc. Zool. Soc, p. 239.

Palythoa couchii:

Fischer, 1874, Nouv. Arch. Mus., Paris, pp. 235, 239 ; 1874, Cornptes rendus, lxxix.,
p. 1209 (trans. 1875, Ann. Mag. Nat. Hist. (4), xv., p. 374) ; 1875, Actes Soc. linn. Bordeaux,
xxx., p. 8.
Polythoa arenacea:

(Not of D. Ch.) Andres, 1884, var. coiwhii, Le Attinie, p. 308 ; Pennington, 1885, var. linearis,
Brit. Zooph. (in part), p. 182.

Palythoa arenacea:

(Not of D. Ch.) Carus, 1884, Prod. Faunas Medit., p. 75.

Form. — Column cylindrical, rising to about three or four times its diameter.
Margin cut into 12 or 14 (generally the latter number) large, fleshy, triangular
teeth, which are connected by a thin web of transparent membrane. In a state
of semicontraction these teeth form strongly marked, converging ridges on the
flat summit of the column. Incrustations of fine sand. When the column is
much distended, the grains of sand become considerably separated, and the
visceral cavity can be seen through the transparent and smooth integuments.
Disc, generally flat or slightly concave, but protusile in a conical form ; radii
distinct. Tentacles 28 (or 24), bicyclic, those of the inner row correspond to the
marginal teeth ; they are subequal, they taper gradually, are bluntly pointed,
and about equal in length to the diameter of the column. Ccenenchyme,
narrow, irregularly creeping, soft, invested with sand like the column.

Colour. — Column and ccenenchyme pale brown ; disc pellucid, reddish-gray,
dusted with excessively minute white specks; tentacles translucent, nearly
colourless, opaque white tip ; lip opaque white.

Dimensions. — " One-eighth of an inch [3 mm.] in diameter, and about thrice
that height [9 mm.] in extension. In contraction the button is usually about aline
[2 mm.] in height. Mr. Holdsworth has obtained specimens much larger than
these."

Habitat. — " var. linearis. — The condition above described, in which the root-
band creeps in a narrow ribbon over stones and shells. Cornwall and Devon."

The foregoing description is taken from Gosse, and refers to the specimens he
had seen alive ; perhaps he has incorporated older observations in it.

We have not been able to see any specimens of this species from the recorded
localities, although we have made numerous efforts to do so. Our generous
friend Canon Norman put some Zoanthese from the Channel Islands at our
disposal, which bear a very strong superficial resemblance to E. couchii, as defined

646 Haddon and Shackleton — A Revision of the British Actiniae.

above ; unfortunately they had been dried at some time or other, although they
were in spirit when we had them, and though we made sections of them we could
not make any satisfactory observations.

In order to facilitate the work of future observers we abstract all the
additional information about this species, which is valuable from a descriptive
point of view.

Johnston (1847) defines the genus and species as follows: — " Zoanthus :
polypes distant, united by a creeping, root-like, fleshy band. Z. couchii: body
cylindrical; tentacula in several circles." In quoting from Couch he adds the
following details: — "It is a very small species ... of a light sandy or opaque
red colour, and its surface is minutely glandular [this is an error of observation,
and probably refers to the grains of quartz]. In its contracted state it is sub-
conoidal, resembling both in shape and size a split pea. When semi-expanded it
elevates itself to about twice its former height, and becomes contracted about its
middle into an hour-glass form. When fully expanded the tentacula become
distended and elongated to about the length of the transverse diameter of the
body ; and they are generally darker at their extremities than towards the base."

Holdsworth (1858) obtained some specimens from 10-12 fathoms off Torbay.
" One group of six polypes on the inside of a valve of Cardium rusticum is
arranged in a linear series ; . . . others are scattered over the surface of a flat stone,
and have no perceptible connexion with one another, except in a few instances
when two or three of them are united. . . . The body forms a cylinder from 2 to 4
lines [about 4 "5— 9 mm.], by about half that in breadth, and is clothed with a
dense coating of fine sand, which at the upper extremity is divided into 14 deeply-
cut, marginal teeth ; these cover the top of the column when the animal is closed.
The tentacula are moderate in length, slightly tapering, smooth. . . . They are
arranged in two rows containing 14 each, of which the inner series are rather the
longer, and are placed opposite the angular prolongations of the column, those of
the outer row alternating with them. . . . The general colour of the disc and
tentacula is a pale transparent brown, becoming opaque white around the mouth
and at the tips of the arms, and all the intermediate parts are finely speckled
with the same tint." The following year (1859) he obtained some much larger
specimens from Torbay.

Hincks (1861) says, "Not uncommon: Salcombe Bay [Devonshire], on slate,
stone, &c. (in about 12—15 fathoms)."

The following is a description of an Epizoanthus dredged by one of us in the
S. W. of Ireland, and which we refer with some hesitation to this species. If
E. rubricornis should prove to be a different species from E. couchii, our form will
probably be found to be the same as the former, although the tentacles are of a
different colour, and the habit of growth is different.

Haddon and Shackleton— A Revision of the British Actinia? .

647

Form. — The column is elongated, tapering from above downwards ; the body-
wall is well incrusted, but when the sand is rubbed off, the body-wall is thin and
translucent. The capitulum has about 14 ridges ; these may be present or absent
in preserved specimens ; in the latter case their absence appears to be due to their
being rubbed when in the dredge. Tentacles bicyclic, about 14 in number in
each cyle, the inner being slightly the longer and more curved. Mouth linear, on
a slight cone. Ccenenchyme, thin, either band-like, or forming small expansions.

Colour. — Sandy, sometimes dull, tawny-orange when alive ; disc translucent
buff, lips white, pale radii ; tentacles translucent buff, opaque-white spot at tip.

Dimensions. — Usually about 10—14 mm. in height, and 2-3 mm. in diameter at
the top of the contracted specimens, occasionally reaching a height of 18—20 mm.,
with a diameter of 4*5—5 mm.

Habitat. — S. W. Ireland ; about 30 miles off Cape Clear (PI. lviii., figs.
27, 28), 80 fathoms; 40 fathoms off Glandore, Co. Cork ; Berehaven, Bantry
Bay, 10 fathoms (A. C. H.), (PI. lviii., fig. 26), [Proc. Roy. Irish Acad. (2), iv.,
Sci., 1886, in which Report Mr. S. O. Ridley identified this form as Palythoa
arenacea(?), D. Ch., p. 617].

The Rev. Canon Norman has sent us specimens of an Epizoanthus from
Birterbuy Bay, Co. Galway. They were unfortunately too badly preserved for
us to be able to study them minutely, but at all events the sphincter muscle
closely resembles that of our specimens from S. W. of Ireland, and externally
they agreed fairly well with the English specimens of this species. Some very
similar Channel Island specimens (identified as " Z." couchii), which he gave us at
the same time, probably belong to this species.

Fischer's (1874) description is as follows : — " The base of the colony is clothed
with a layer of agglutinated sand, extending more or less ; the polyps, irregularly
disposed, have their column protected b}7 a coating of sand ; this is cylindrical and
elongated when completely extended ; colour cindery-gray ; the superior border has
14 to 15 teeth. The tentacles, disposed in two rows, are short, whitish, and to the
number of 28—30. The disc is whitish ; the mouth small, transverse."

The specimens came from " Arcachon, from 20-45 brasses. The colonies were
fixed on to the shell of Chenopus pes-pelicani, which gives lodging to a Sipunculus.
Alder has identified it at Guernsey. M. Sauvage has obtained it at Boulogne on
Pecten maximus, dredged in the channel " (p. 235). In his " bathymetrical distri-
bution " he records this species on the oceanic coasts of France, from the Nullipore
zone (28—72 metres), p. 239. The other Papers are merely abstracts.

To sum up the history of this species we may put the present state of our
knowledge in this form. Johnston quotes Couch's description of the Cornish type
specimens. Gosse, Holdsworth, and Hincks obtained Devonshire specimens which
are probably the same as the former. Forbes identifies it as having been dredged

648 Haddon and Shackleton — A Revision of the British Actinice.

by Mac Andrew in Loch Fine, W. Scotland, in 1844. Thompson records it as
having been dredged by himself and Iiyndman in 1835 and 1846, 15—20 fathoms,
from Strangford Lough (N.E. Ireland). Wright and Greene copy this. It may or
may not be this species. We now describe specimens from S. W. Ireland which
may possibly be this species : Fischer identifies it from the N. and W. coasts of
France. Andres and Pennington merely quote Gosse.

Body-wall (PI. Lix.,"fig. 4). — The body-wall is extremely thin in this species.
The ectoderm, where present, is continuous, and is covered by a thin cuticle. It
contains occasional nematocysts. Incrustations, which consist chiefly of grains
of sand, are fairly numerous. Cell-enclosures are very rare. The endoderm
is very thin, and of uniform thickness. The muscular layer is rather feebly
developed.

Sphincter muscle. — The single mesogloeal sphincter is well developed, although
it is not so powerful as in the free variety of E. incrustatus. It consists of
elongated cavities which are well filled with muscle-fibres, the cavities form-
ing for the most part a single row (PI. lx., fig. 3).

Disc and Tentacles. — The structure of the disc and tentacles is for the most part
as in other species of ZoantheEe ; but oval nematocysts, similar to those which are
found in the ectoderm of the body-wall and of the oesophagus, are present in the
ectoderm of the tentacles of more than one of the specimens which we have cut.
We have not, however, found them in all our specimens.

(Esophagus. — The ectoderm of the oesophagus is thrown into folds which appear
to be deeper as a rule in the short than in the longer specimens. There is a well-
marked groove. Nematocysts are generally to be found in this region ; but in
one or two specimens we have not been able to find them. In some cases they
are very abundant. Sometimes they appear to contain black pigment-granules.
In other cases they are quite clear, containing a distinct, coiled thread.

Mesenteries. — The mesenteries present the usual macrocnemic arrangement.
The imperfect mesenteries are fairly well-developed. The longitudinal muscles are
borne upon mesogloeal plaitings which are frequently well-marked, but in some
of our specimens they are much slighter than in others. Nematocysts are very
abundant in the ectoderm, which forms the mesenterial filaments in the usual
manner.

Gonads. — We found no gonads in any of our specimens.

Haddon and Shackleton — A Revision of the British Actinice.

649

[Epizoanthus arenaceus (D. Ch.), (not British, Mediterranean). {Polythoa (str. s.)
arenacea. Andres, 1884, p. 308. Type var. Palythoa arenacea, Carus, 1884.
p. 75.)

(PI. lix., fig. 7; PI. lx., fig. 4.)

Form. — Column cylindrical. Body-wall, thick and opaque, sometimes
transversely wrinkled, about 15 capitular ridges and 30 tentacles; coenenchyme
incrusting, with a tendency to form linear bands.

Colour. — Dirty sand (in spirit).

Dimensions. — Height, 7-12 mm. ; diain., 3*5— 4*5 mm.

The above description is taken from specimens identified at the Naples
Zoological Station. It will be seen that E. arenaceus differs from E. eouchii,
chiefly in the great thickness of its body-wall, which gives it a very characteristic
appearance (PI. lix., fig. 7). Our specimens were not well preserved, and we have
therefore some difficulty in determining satisfactorily anatomical characters. The
mesogloeal sphincter muscle differs from that of E. eouchii in the appearance of its
cavities, the muscle-fibres being arranged in a single row round the mesoglcea,
leaving an empty space in the centre of the cavity (PI. lx., fig. 4). The thickness
of the body-wall can be well seen in transverse sections. Nematocysts are
present in the ectoderm of the oesoDhagus, and in the mesenterial filaments.]

Epizoanth macintoshi, n. sp.

(PL lviii., fig. 29 ; PI. lix., fig. 1.)

Form. — Short, very stout, rigid column, incrusted with foraminifera which give
it a very characteristic, white, granular appearance. Upper surface of contracted
column with 18 radial ridges. Cceneu chyme apparently linear, of same nature as
the wall of the column.

Colour. — Grayish white.

Dimensions. — (In spirit) one polyp, 7 mm. high by 6 mm. in diameter ; the
other, 5 mm. high by 4*5 mm. in diameter.
Locality. — Shetlands (1871).

A small colony of three specimens of this species was kindly handed over to us
by Dr. W. C. M'Intosh, F.E.S., Professor of Zoology at St. Andrews. One of these
we devoted to the microtome ; the remaining specimens are in Prof. M'Intosh's
collection. We are pleased to be able to associate such a well-marked species
with the distinguished Scottish Zoologist who has placed his collection of Actiniae
at our disposal.

TRANS. EOT. DUB. SOC, N.8. VOL. IT., PART XII. 4Z

650

Haddon and Shackleton — A Revision of the British Actinice.

Body-wall (PI. lix., fig. 1). — The ectoderm is much broken, owing to the
incrustations. Where present it is continuous, and is covered by a thin cuticle.
Thread cells, containing a few, almost black, pigment-granules, are occasionally to
be met with amongst the columnar cells of the ectoderm. The mesogloea is
thinner relatively to the diameter of the column than in most species of Zoantheae.
The incrustations consist almost exclusively of foraminifera, which are frequently
so large that a single specimen extends right across the body-wall, and is partly
embedded in the ectoderm and partly in the endoderm, as well as in the mesogloea.
There are hardly any cell-enclosures in the mesogloea. Single cells only are
occasionally to be seen enclosed. The endodermal muscular layer appears to be
fairly well developed. The endoderm is formed by a thin layer of columnar cells
of uniform height.

Sphincter muscle. — The single niesoglceal sphincter is thick, extending right
across the wall of the capitulum. The cavities in the mesogloea are large.

Disc and Tentacles. — The nuclei of the ectoderm are diffused, and do not form a
central band. The muscular layers are well developed.

(Esophagus. — The ectoderm of the oesophagus appears to be quite smooth, not
being thrown into folds. The groove is well marked, and there is a slight thicken-
ing of the mesogloea in this region.

Mesenteries. — The arrangement of the mesenteries is macrocnemic. Owing to
the presence of a parasitic crustacean in the single specimen we have cut it is
difficult to determine the details regarding the mesenteries. The imperfect
mesenteries extend but a short way into the body-cavity. The mesogloea is
well developed, and is thrown on one side of each mesentery into distinct plaitings,
which support the longitudinal muscle-fibres. The parieto-basal muscles are less
well developed, and appear to extend but a short way from the body-wall.

Gonads. — We found no gonads.

Parasitic Crustacean. — It is impossible to determine the nature of the crustacean
infesting our specimen, or to say whether it is a fully developed or a larval
form.

[Epizoanthus norvegicus (Kor. & Dan.). (Not British, Norway.)

(PI. lix., fig. 5.)

Form. — Rather more clavate than E. macintoshi ; ccenenchyme forming expan-
sions, in which the polyps, in the specimens we have examined, appear to have
a tendency to form linear series.

Colour. — Sandy brown (in spirit).

Dimensions. — Height, 6-12 mm. ; diam., about 6 mm.

Haddon and Shackleton — A Revision of the British Actinias. 651

We are again indebted to our friend Canon Norman for specimens (identified by
Danielssen) of this species. Outwardly it differs from E. macintoshi in the rather
more clavate form mentioned above, and in the darker and more brownish colour.
Our specimens of either species are not sufficiently numerous to lay much stress
on the difference in the coenenchyme, which in many species varies much according
to the nature of the body to which the polyps are attached. Anatomically the
two species can be readily distinguished. The ectoderm of the body-wall in E.
norvegicus is very thick, and is crowded with nematocysts (PI. lix., fig. 5). In
E. macintoshi the ectoderm is very thin relatively to the diameter of the column,
and contains very few nematocysts (PL lix., fig. 1). The incrustations in E.
norvegicus are various, consisting of spicules, grains of sand, and foraminifera. In
E. macintoshi they consist almost exclusively of foraminifera. The endoderm also
in E. norvegicus is much thicker than in E. macintoshi. The imperfect mesenteries
in E. norvegicus are remarkably well developed. In E. macintoshi they are feebly
developed, extending a very short way into the body-cavity.]

Epizoanthus wrightii, n. sp.

(PL lviil, figs. 30-33 ; PL lix., fig. 3 ; PL lx., fig. 2.)

Form. — Column somewhat thick-set, body-wall incrusted but not particularly
rigid, 16 capitular ridges, mouth a narrow slit, with one oesophageal groove;
tentacles 32 in number, bicyclic, transversely corrugated when not fully extended.
Coenenchyme broad, flat, irregular. Polyps arise from the coenenchyme ;
craspeda ejected from the mouth when irritated.

Colour. — Dirty pellucid- white or orange-pink ; in both the disc is speckled with
opaque white ; tentacles with an opaque white tip ; craspeda, white or orange-pink,
according to the colour of the polyp.

Dimensions. — Height, 13 mm.; diameter of column, 8*5 mm.; diameter of disc,
13 mm. ; length of tentacles, 13 mm. Average height of expanded spirit specimens,
4 mm. ; average diameter of column, 3 mm. In the contracted specimens the
height and diameter are about equal, or the latter may even be the greater.

Habitat. — Dalkey Sound, Dublin Bay ; between tides ; spreading over incrus-
tations on the granite rocks but never actually attached to the granite itself.

We are indebted to the brothers Dixon, for these specimens, and the above
description is mainly taken from an account recently published by them ("Notes
on the Marine Invertebrate Fauna of Dublin," Proc. Roy. Irish Acad., ser. mr,
vol. ii., p. 29, 1891). They very kindly placed all their specimens at our disposal.
We have the pleasure of dedicating this species to our friend Dr. E. Perceval

652

Haddon and Shackleton — A Revision of the British Actinice.

Wright, who is so well-known as a student of the Actinozoa, and who is always
so ready to help his scientific colleagues.

Body -wall (PI. lix., fig. 3). — The ectoderm, where present, is continuous.
It consists of numerous granular and deeply staining columnar cells, with
occasional nematocysts scattered amongst them. It is protected by a thick
cuticle, which does not stain but is of a dark brown colour owing to the presence
of dark brown granules and of various foreign bodies. Incrustations chiefly
consisting of coarse grains of sand, with a few foraminifera, are embedded in
the mesoglcea, which contains very few cell-islets or other enclosures. The endo-
derm is formed by a rather thin layer of ordinary columnar cells. The endoder-
mal muscular layer appears to be but slightly developed.

Sphincter muscle. — The single mesogloeal sphincter consists of several rows of
simple cavities at the distal end. Proximally it is reduced to a single row of
very small cavities (PI. lx., fig. 2).

Disc and Tentacles. — There is little worthy of note in the structure of the disc or
tentacles. Both ectodermal and endodermal muscular layers are well developed.

(Esophagus. — The ectoderm of the oesophagus is thrown into well-marked folds ;
there is a distinct groove, but little if any thickening of the mesogloea in this
region.

Mesenteries. — The mesenteries have the usual macrocnemic arrangement. The
imperfect mesenteries are distinct, although they extend but a short way into the
body-cavity. The reflected ectoderm forms the mesenterial filaments in the usual
way. The mesoglcea is not very well developed ; both parieto-basilar and
longitudinal muscles form almost simple layers. The endoderm is thinner than
that of the body-wall, and contains in addition to the ordinary columnar cells,
small oval cells which stain a very deep carmine.

Gonads. — No gonads were present in the specimens examined by us.

PEOBABLY BELONGING TO THIS GENUS.
Zoanthus rubricornis, Holdsworth.

Zoanthus rubricornis :

Holdsworth, 1861, Proc. Zool. Soc. : and Ann. Mag. Nat. Hist. (3), vn., p. 484, woodcut.
Hincks, 1861, loc. cit. (8), vrn., p. 364.

Polythoa (Endeithoa) rubricornis :

Andres, 1884, Le Attinie, p. 316.

Form. — An unattached group of ten polyps, each gradually tapering from
above downward, incrusted with sand ; marginal serrations not nearly so
conspicuous as in E, couchii.

Haddon and Shackleton — A Revision of the British Actinice. 653
Colour. — Tentacles a distinct red.

Dimensions. — Largest polyp, 25 mm. in height, and about 5—6 mm. diameter at
the top when contracted. (Judging from the figure, 20 mm. is the average height,
and 5 mm. the capitular diameter.)

Habitat. — Plymouth Sound.

This species has apparently never been met with since its discovery ; and we
are unable to do more than recast Holdsworth's description. We have no doubt
that this species is an Epizoanthus ; and it very closely resembles in outward
appearance the specimens of E. couchii, which one of us has dredged off S. W.
Ireland, the habit of growth being the most distinguishing feature, and upon this
we do not place any reliance. Should this species be found to be distinct from
E. couchii we expect that our Irish specimens would have to follow the former.

PARAZOANTHUS, n. g.

Macrocnemic Zoanthese, with a diffuse endodermal sphincter muscle. The
body-wall is incrusted. The ectoderm is continuous. Encircling sinus as well as
ectodermal canals, lacunae, and cell-islets in the mesoglcea. Dioecious. Polyps
connected by thin ccenenchyme.

This is a very well marked genus anatomically ; but it is often impossible to
distinguish between certain species of this genus and those of Epizoanthus on
external examination only.

We have taken for our type P. axinellce (Schmidt), as this form is so readily
obtainable, and, thanks to the Naples Zoological Station, is to be found in most
museums. Another advantage is that it is one of the easiest of the incrusted
Zoanthese to study microscopically.

Erdmann was the first to separate the macrocnemic Zoanthese, with a diffuse
endodermal sphincter, from those with a mesoglceal muscle. He rightly retained
the genus Epizoanthus for the latter, but wrongly referred the former to Palythoa,
of which he also took P. axinellce as the type. We have elsewhere (1891)
entered into a detailed discussion of our reasons for restoring Palythoa to its type
species P. mammillosa (E. & S.), and we consequently have to erect the new genus
defined above.

BRITISH SPECIES OF THE GENUS PARAZOANTHUS.

P. anguicoma (Norman), 1868.
P. dixoni, n. sp.

654 Haddon and Shackleton — A Revision of the British Actinice.

SYNOPSIS OF BEITISH SPECIES OF PARAZOANTHUS.

(exteenal chaeacters.)

Coenenchyme thin, band-like, or inconsiderable ; capitular ridges about 18,

prominent, granulated, ....... P. anguicoma.

Coenenchyme thick, soft, expanded ; capitular ridges about 21 ; not so prominent

as in former, ........ P. dixoni.

(anatomical characters.)

Mesenteries project only a short distance from the body-wall into the ccelenteron ;

endoderm of moderate thickness, uniform ; incrustations numerous, . P. anguicoma.

Mesenteries project a considerable distance from the body-wall into the ccelen-
teron ; endoderm forming very thick ridges between every two mesenteries ;
incrustations few, ........ P. dixoni.

The following species is inserted for comparison with the above :-

Coenenchyme thin, band-like or irregular expansions ; capitular ridges 13-15, not ^
very prominent, ........

Mesenteries much as in P. anguicoma ; endoderm very thin and uniform ; incrus-
tations not very numerous, chiefly spicular, ....

P. axinella
( Mediterranean) .

Parazoanthus axinellee (Schmidt).
Type species. — (Not British.)
(PI. lix., fig. 8; PI. lx., figs. 6, 7.)

Palythoa axinella :

Schmidt, 1862, Spongien des Adriatischen Meeres, p. 61, pi. vi., figs. 2, 3. Gray, 1867, Proc.
Zool. Soc, p. 238. Heller, 1868, Ber. k. zool., bot., Gesellsch., Wien, p. 21. Jourdan, 1880,
Ann. des. Sci. Nat. (6), x., p. 43. Muller, 1883, Morphologie Palythoa u. Zoanthus, p. 8.
Carus, 1884, Prod. Faunae Medit., p. 76.

Zoanthus axinella; :

Koch, 1880, Morph. Jahrb., vr., p. 359, pi. xvi., figs. 1-6.

Polythoa (str. s.) axinella :

Andres, 1884, Le Attinie, p. 311, pi. x., fig. 7.

Form. — Polyps obconical, coated with foreign particles ; capitular ridges,
13-15, not very distinct. Tentacles, 26—30; pointed with a very slight

Haddon and Shackleton — A Revision of the British Actinice.

655

terminal swelling, perforated. Coenenchyme band-like, linear, adhering to
sponges ; polyps usually in linear groups of three or four, sometimes solitary.
Colour. — Yellowish.

Dimensions. — Height, 7 mm. ; diameter, 3 mm. ; tentacles, 5—10 mm.
Habitat. — On various sponges, also on corallines > and stones. Adriatic,
Marseilles, Naples.

The foregoing description is compiled from the accounts given by Andres and
Carus. In the specimens we have examined, as sent out by the Naples Zoological
Station, we find that there is a considerable variation in the size of the polyps,
some attaining a height of 13 mm., and the coenenchyme forms an irregular
expansion on which the polyps are very crowded. The following anatomical
account is based upon these specimens. We leave it for others to determine
whether more than one species is commonly identified as P. axinellce. Koch's
specimens appear to be the same as ours, so far as his description and figures go.
The Adriatic specimens require re-investigation.

Body-wall (PI. lix., fig. 8). — The body- wall is covered with a delicate
cuticle, beneath which lies a rather thin layer of continuous ectoderm. Numerous
oval nematocysts, which do not stain, are generally to be found among the
granular and deeply staining columnar cells of the ectoderm. Incrustations,
consisting for the most part of sponge spicules, are scattered, sometimes thickly,
sometimes more sparingly, through the mesoglcea. Beneath these incrustations,
separated from the endoderm by a thin layer of mesoglcea, lies an encircling
sinus, containing deeply staining nuclei and cell contents, as well as numerous
nematocysts similar to those which are found in the ectoderm. The sinus is
frequently interrupted by bars of mesoglcea of variable thickness, so that in cross
section it often appears to consist of a circular series of rather narrow lacunae.
Canals frequently branch off from the sinus, and in many cases their connexion
with the ectoderm can be distinctly seen. Single isolated cells are occasionally
found enclosed in the mesoglcea. The endoderm forms a very thin and almost
uniform layer.

Sphincter muscle. — The sphincter muscle is, as described by Erdmann, diffuse
and endodermal.

Disc and Tentacles. — There is nothing worthy of special note in the structure
of the disc and tentacles.

(Esophagus. — The groove is well marked, and the mesoglcea is considerably
thickened in this region (PI. lx., fig. 6 J.

Mesenteries. — The arrangement of the mesenteries is macrocnemic. The
imperfect mesenteries are well developed, often reaching nearly half way from the
body-wall to the oesophagus. The longitudinal muscles are well developed in the
upper part of the mesenteries, close to the disc, the fibres being supported in this

656 Haddon and Shackleton — A Revision of the British Actinice.

region by well developed mesogloeal plaitings. Lower down the plaitings
disappear, the muscles forming an almost simple layer. Close to the disc a bundle
of transverse fibres are seen on the opposite side of each mesentery to that which
bears the longitudinal fibres. These seem to be the prolongations of the
endodermal muscles of the disc and tentacles. The reflection of the ectoderm of
the oesophagus, and its connexion with the filaments, can be well seen in this
species (PI. lx., fig. 6). The mesoglcea and the endoderm appear to be
involved to some extent in the reflection also. The endoderm of the mesenteries
forms, for the most part, a very thin layer, but it is much thickened in the region
of the filaments (PI. lx., fig. 7), the mesenteries in this region resembling those of
Z. macgillivrayi (PI. lxiv., fig. 8), but the thickening is not so marked as in that
species, nor do we find here either zooxanthellse or nematocysts.

Gonads. — In one of our specimens male gonads are present. They are
surrounded by a thickened layer of endoderm (PI. lx., fig. 7).

Parazoanthus anguicomus (Norm.).
(PI. lviii., figs. 34-36; PL lix., figs. 11, 12.)

Zoanthus sulcatus ? :

Bowerbank, 1867, Prioc. Zool. Soc, p. 351.

Zoanthus anguicoma :

Norman, 1868, " Shetland Report," Rep. Brit. Assoc., p. 319.
Polythoa (Tceniothoa) anguicoma :

Andres, 1884, Le Attinie, p. 317.

Palythoa, sp. :

Ridley, 1886, Proc. Roy. Irish Acad. (2), nr., Sci., p. 617.

Palythoa anguicoma :

Hertwig, 1888, Suppl. "Challenger" Rep., Actiniaria, p. 46, pi. i., fig. 7. Is probably
not P. anguicoma, but an allied species, P. hertwigi, n. n.

Form. — Body rigid, rough; in some specimens the column has an almost warty
appearance; capitular region swollen when contracted; radial ridges about 18 in
number, prominent, rough. Tentacles in two cyles, of about 17 in each, very long
and extensile, more than equal to diameter of disc when fully expanded; gradually
attenuating to very slender points. Coenenchyme incrusted, thin, either band-like,
creeping on sponges and other objects, or forming broader expansions. The
coenenchyme is never well developed, and sometimes the polyps are isolated or in
small groups. The smaller specimens, when contracted, have a button-like
appearance.

Colour. — Pinkish-white (Norman); sand colour in preserved specimens.

Haddon and Shackleton — A Revision of the British Actinia?.

657

Dimensions. — " Column, 3-5 times as high as broad " (Norman). Height of
column, when fairly extended (in spirit), 13 mm. ; diameter of withdrawn
capitulum, 3— 4 mm. In the "button" condition the height is much less, about
4—5 mm., or even less. Some West of Ireland specimens have, in spirits, a height
of 15 mm., diameter of capitulum 5—6 mm., diameter of middle of column 3—4 mm.

Locality. — Shetlands, W. and S.W. Ireland. The exact localities for this species
are as follows : — " Living on sponges, PhaJeellia ventilabrnm and P. robusta,
Normania crassa, Oceanapia j'effreysii, &c, in very deep water, 110-170 faths., 20-25
miles N.N.W. off Burrafirth Lighthouse" (A.M.N.), (PI. lviii., fig. 34); St. Magnus
Bay, Shetland, 1867; " Porcupine, 1869, St. 8, 100-159 faths." [off Galway Bay,
W. Ireland]. The foregoing are in Canon Norman's collection. 80 faths., 40 miles
S.W. of Cape Clear, Co. Cork, 1885 (A.C.H.), (PI. lviii., fig. 36) ; 80 faths., off the
Skelligs, Co. Kerry, July 13, 1886 (A.C.H.), (PI. lviii., fig. 35); 126 faths., off
Achill, Co. Mayo, 1890 (A.C.H.).

This species is subject to considerable variation in general appearance, so
much so that we at one time thought that the forms we had under review might
belong to two species. This is the "squat button-like form" of Ridley (I.e.).
There can be no doubt that this is the " Zoanthns sulcatus ? — dispersed in patches
on the surface of Desmacidon Jeffrey sii, from Shetland," of Bowerbank. Hertwig
(1888, Suppl. "Chall." Rept. Actiniaria, pp. 446-48) doubtfully refers a colony
of "Palythoa" to this species from Inaccessible Island, Tristan d'Acunha (S.
Atlantic), 60—90 faths. From Erdmann's anatomical investigations of these
specimens it is certain that they belong to the genus Parazoanthus. The species is
certainly very close to P. anguicoma ; but we consider that the slight differences
in the external characters, together with the " considerable hollow expansion " of
the encircling sinus ("ring-canal") invariably opposite the insertion of the
mesenteries, are sufficient to separate the two species, and for the latter we would
propose the name of Parazoanthus hertwigi.

Body-wall (PI. lix., figs. 11, 12). — The ectoderm, where present, is continuous,
and is covered by a thin cuticle. It forms a layer of variable thickness, and
consists of columnar cells containing deeply staining granules, and of oval
nematocysts which do not readily stain. Incrustations, consisting of sand spicules,
foraminifera, &c, are fairly numerous, and are embedded both in the ectoderm
and in the mesoglcea. There is a well-developed encircling sinus, which lies
beneath the incrustations. It is of variable thickness, and is frequently crossed
by strands of mesoglcea ; but these strands are not at all so thick as those in
P. axinellce, and the sinus in consequence presents a much less broken appearance
than in that species. Branching and anastomosing canals, very similar to those
which we describe for Z. coppingeri (1891), connect the encircling sinus with
the ectoderm. Nematocysts are frequently to be found in the encircling sinus.

TRANS. ROY. DUB. SOC, N.S. VOL. IT., PART XII.

658 Haddon and Siiackleton — A Revision of the British Actiniae.

Cell-islets and lucunse are also often enclosed in the mesogloea. The endoderm
forms a thin layer of almost uniform thickness. The diffuse endodermal muscular
layer is well developed.

Sphincter muscle. — The sphincter muscle is diffuse and endodermal, as in other
species belonging to this genus. The mesogloeal plaitings are deep and well
developed, but they branch very slightly.

Disc and Tentacles. — There is little worthy of special note in the structure
of the disc and tentacles. The ectodermal muscles are exceedingly well
developed.

(Esophagus. — The ectoderm of the oesophagus is generally thrown into folds,
but these are in some cases very slight. There is generally a well-marked
groove, the mesogloea being here somewhat thickened. Occasionally cell-islets
are to be found in this region.

Mesenteries. — The arrangement of the muscle is macrocnemic. The imperfect
mesenteries generally extend well into the ccelenteron. The longitudinal muscles
vary considerably in the degree to which they are developed, not only in
individuals, but in different parts of the same individual. In some cases they
form an almost simple layer, whilst in others they are supported on well-
developed plaitings of the mesogloea. The filaments are formed by the con-
tinuation of the ectoderm in the usual manner. Immediately below the oesophagus,
the perfect mesenteries, bearing the filaments, extend but a short distance into the
ccelenteron, leaving considerable empty space in the centre. Lower down they
again increase in size, and near the base of the polyp they contain sinuses which
appear to be of the same origin as the ectodermal enclosures of the body-wall.

Gonads. — There were no gonads in the specimens of this species which were
examined by us.

Parazoanthus* dixoni, n. sp.

(PI. lviil, figs. 37, 38; PI. lex., figs. 9, 10 ; PI. lx., figs. 8, 9.)

Form. — Body long, cylindrical, or quite short, smooth, or slightly roughened,
very few incrustations. Polyps crowded, sjjringing irregularly in all directions
from an expanded, soft, thick ccenenchyme. Buds often arise from close to the
bases of the older polyps. Scarcely any diminution in the length of the
contracted polyps is noticeable as compared with the expanded specimens. The
upper end of the contracted specimens is swollen, and has about 21 inconspicuous

* We name this species in honour of our friends the brothers Gr. Y. and A. F. Dixon, who have done
much valuable work in connexion with the Irish Actiniae.

Haddon and Shackleton — A Revision of the British Actinia?. 659

radial ridges. Disc with distinct radii ; mouth ellipsoidal, lips prominent.
Tentacles in two cycles of about 21 in each; length about the diameter of the disc.

Colour. — Creamy white ; polyps with a slight pinkish tinge.

Dimensions. — (In spirit). A. The larger specimens : height of column, 20 mm. ;
diameter, 4-5 mm. ; diameter of disc and tentacles, 10 mm. ; the coenenchyme of
one colony measured 60 mm. by 30 mm. (PI. lviil, fig. 37). B. Medium specimens:
height of column, 16 mm. ; diameter, 3 mm. ; average diameter of disc and
tentacles, 9 mm. C. Small variety : average height of column, 5 mm. ; diameter,
4 mm. (PI. lviil, fig. 38).

Locality. — West of Ireland (5—8 miles W. of the Great Skellig, Co. Kerry,
70-80 faths., July 13, 1886. A. C. H.). This species was also obtained by the
" Porcupine " in 1869. (No locality. Norman collection).

Body-wall (PI. lix., figs. 9, 10). — The ectoderm is continuous, and is covered by
a thin cuticle. It forms a thick layer, consisting of very granular columnar cells,
which stain deeply, and of numerous nematocysts which do not stain. The
nematocysts in this species are scattered throughout the ectoderm in a fairly
uniform manner. Incrustations consisting of spicules, grains of sand, and
f oraminifera may be found scattered at intervals through the mesoglcea, but in our
specimens of the larger variety these are very rare. Beneath the incrustations
lies a well-developed encircling sinus. It is frequently broken by strands of
mesoglcea, and is connected with the peripheral ectoderm by numerous branching
and anastomosing canals, very similar to those we find in P. anguicoma. The
encircling sinus is connected with the endoderm by the fibrils or canalaculi of the
mesogloea, which are numerous and very distinct in our sections. The endoderm
is not of uniform thickness as in P. anguicoma, but becomes very thick in the
centre of each endocoele and ectoccele, thus forming a longitudinal ridge between
every two mesenteries. The diffuse endodermal muscular layer is well developed.

Sphincter muscle (PI. lx., fig. 8). — The diffuse endodermal sphincter is well
developed, but very simple in character, the mesoglcea being raised into distinct
but unbranched plaitings. In some sections some of these plaits appear to unite
so as to enclose part of the muscle entirely in the mesoglcea, but we are uncertain
whether this appearance is not due to the direction in which the sections are cut.

Disc and Tentacles. — There is little worthy of note in the structure of the disc
and tentacles. The ectodermal muscular layer is well developed.

(Esophagus. — The ectoderm of the oesophagus is thrown into deep folds, into
which the mesogloea also enters. There is a deep, well-marked groove, and the
mesogloea is here very much thickened.

Mesenteries. — The arrangement of the mesenteries is macrocnemic. The
imperfect mesenteries are well developed, and extend into the body-cavity nearly
half-way between the body-wall and the oesophagus. The ectoderm of the

5 A 2

660 Haddon and Shackleton< — A Revision of the British Actinice.

oesophagus is connected with the filaments in the usual manner. The mesogloea of
the mesenteries is well developed in all our specimens, and is thickened as well as
raised into distinct plaitings on that side of each mesentery which bears the longi-
tudinal muscle fibres (PI. lx., fig. 9). The parieto-basal muscles are not so well de-
veloped as the longitudinal ones; and they extend along each side of the mesenteries,
but a short way into the ccelenteron ; there is therefore no difficulty in distinguishing
between the two sets of muscles ; and the pairing of the mesenteries can be very
distinctly seen in this species. The endoderm of the mesenteries is thinner than
that of the body-wall. The perfect mesenteries, from the termination of the
oesophagus downward, extend far into the ccelenteron, which is, in consequence,
almost filled up by the mesenteries and their filaments. Transverse sections of
P. dixoni, taken just below the oesophagus, present in consequence a very different
appearance from those of P. anguicoma taken from the same region. In our
specimens of the small variety we find well-marked sinuses in the mesogloea of the
mesenteries, extending from the ccenenchyme a short distance upward into the
ccelenteron, disappearing at about the lower termination of the mesenterial
filaments. These sinuses are very similar in appearance to the ectodermal sinuses
of Z. copping eri^ but we are unable to find in them any connexion with the
ectodermal canals of the body-wall, whilst in several places they appear to be
distinctly connected with the endoderm. We do not find these sinuses in the
mesenteries of any of those specimens of the larger variety of P. dixoni which we
have cut.

Gonads. — We have found no gonads in our specimens of this species.

OF UNCERTAIN POSITION.
Zoanthus sulcatus, Gosse.

Zoanthus sulcatus :

Gosse, 1860, Brit. Sea Anemones, p. 303, pi. rx., fig. 7 ; pi. xn., fig. 2. Hincks, 1861, Ann.
Mag. Nat. Hist. (3), vm., p. 364.

Gemmaria (?) sulcata :

Gray, 1867, Proc. Zool. Soc, p. 238.

Pahjthoa sulcata :

Fischer, 1874, Nouv. Arch. Mus. Paris, pp. 236, 239 ; 1874, Comptes rendus, lxxix., p. 1207
(trans. Ann. Mag. Nat. Hist. (4), xv., p. 374) ; 1875, Actes Soc. linn. Bordeaux, xxx., p. 8 ;
1887, Arch. Zool. exp. gen. (2), v., pp. 435, 437. Jourdan, 1890, Bull. Soc. Zool., xv., p. 175.

Polythoa (Taniothoa) sulcata :

Andres, 1884, Le Attinie, p. 317. Pennington, 1885, Brit. Zooph., p. 183.

Form. — Column generally cylindrical, but versatile ; upper third of extended
column free from sand, and indented with twenty-two longitudinal sulci ; lower
portion sparsely incrusted with very fine sand. Disc saucer-shaped. Tentacles,

Haddon and Shackleton — A Revision of the British Actiniae.

661

42, in two rows, the inner row corresponding in position to the marginal teeth,
the outer intermediate ; sub-equal, conical, pointed, usually radiating horizontally.
Ccenenchyme band-like, often bearing three polyps abreast, loosely invested with
coarse sand.

Colour. — Column dull uniform olive, each intersulcus having a blackish spot
near its summit ; each tooth is silvery white. Disc olive-yellow ; tentacles
colourless, transparent, with yellow-brown pigment granules.

Dimensions. — Column about 3 mm. high, and about 2 mm. wide.

Locality. — Torbay, on rock, between tidemarks.

Hincks (I.e., p. 364) says: — "Mr. Gosse mentions a single colony of this
pretty but very minute species as having occurred to him at Broadsands, near
Brickham, on sandstone rock. On the opposite side of Torbay, however, and very
close to Torquay, I have found it abundantly in the small basins hollowed out in
the limestone. The Zoanthus forms little colonies on the floor of these miniature
pools ; but they may readily be passed over as tufts of some minute weed." Mr. G.
Y. Dixon informs us that he has carefully hunted over the rock where Gosse
obtained his original specimens, without being able to re-discover this species.

Fischer (1874, p. 236) describes this species as follows: — " Column covered in
its superior half with very fine and agglutinated sand, uniformly brownish or
olive, with 22 rays or ridges, on which one sees grains of sand arranged in ver-
tical lines. The superior border of the column is indicated by a dentate border ;
the teeth are 11 in number, and their colour is white. The disc of the same colour
as the column appears rayed. The tentacles to the number of 22 are arranged in two
rows; the 11 tentacles of the inner row are longer than the marginal by a third or
a fourth. They are conical, transparent, ornamented with some brown spots ;
their extremities have an opaque white colour. The yellow mouth is not
prominent."

" I have found this species at the landing place of Arcachon, at the limit of low
tide ; it forms very numerous colonies, which have an appearance of the perforating
sponges (Cliona), but their colour is more pronounced. The colony is fixed upon
an expansion thickened by sand and other adherent matter. This is perforated by
circular holes for the emission of the Zoanthese, which sink in and disappear when
they are disturbed. M. Lafont has met with this species at Gu^thary, on rocks.

" The figure given by Mr. Gosse is very bad. . . . The small size, the colour,
the habitat of this species, readily distinguish it from the preceding [E. couchii~].
When it is extended it measures 4 mm. in diameter." It occurs between tides
(littoral zone), p. 239. The other Papers are merely abstracts.

Later (1887), Fischer gives the following French localities: — " Le Croisic,
Piriac (Region armoricaine) ; Arcachon, Gue'thary, (Region aquitanique) ; Zone
littorale," p. 435.

662

Haddon and Shackleton — A Revision oj the British Actinia;.

Jourdan has recently (1890, p. 175) identified a form dredged by the Prince
of Monaco (? either from the Bay of Biscay or off the Azores) as u Palythoa sulcata
Gosse."

Zoanthus alderi, Gosse.

Zoanthus alderi:

Gosse, 1860, Brit. Sea Anemones, p. 305, pi. ix., fig. 8 ; pi. xn., fig. 5. Gray, 1867, Proc. Zool.
Soc, p. 234. Pennington, 1885, Brit. Zooph., p. 183. Alder, Trans. Tyneside Nat. Field
Club, v.

Zoanthus (Rhyzanthus) alderi :

Andres, 1884, Le Attinie, p. 328.

Form. — " Polyp inversely conical, the summit being two or more times as broad
as the base ; summit (in the button state) swelling, flat, depressed in the centre, with
many (about twenty ?) radiating strise, indicating the marginal teeth. Surface
smooth, without any investment of sand^ but marked throughout with close-set,
transverse, or annular wrinkles. Ccenenchyme narrow, smooth, irregularly
branching, free from sand."

Colour. — Opaque, milk-white.

Dimensions. — Height of column about two lines (4 mm.) ; greatest diameter
about half a line (1 mm.).

Habitat. — Northumberland ; under-surface of a stone, at extreme low water,
near the " Bear's Rock," Cullercoats (Alder).

This species has not been met with since its first discovery by J. Alder in 1857.
Gosse says: " There were about a dozen polyps in the colony, all of the same
size, which seems to be good evidence that they had attained adult dimensions."
Alder adds that he has " searched for it several times without success." We
cannot help regarding this as an immature form.

No representative of the genus Zoantha, as determined by anatomical investi-
gation, is known to occur in the extra-tropical portion of the North Atlantic.

Until the anatomy of " Z. rubricornis," " Z. sulcatus," and " Z. alderi" is
investigated it will be impossible to tell the genus, let alone the species. The
same criticism applies to the identification of nearly all the Zoanthese.

Haddon and Shackleton — A Revision of the British Actinice.

663

BIBLIOGRAPHY OF THE ZOANTHEiE.

1767. Ellis, J. :

An account of the Actinia sociata, &c. (Phil. Trans. Roy. Soc, lvii., pt. i. (1768), p. 428,
pi. xix.)

1786. Ellis, J., and Solandee, D. :

The Natural History of many curious and uncommon Zoophytes. London, pis.

1798. Cuvtee, G. C. L. D. :

Tableau elementaire de 1' Histoire naturelle des Animaux. (Ann. 6, Journ. de Phys., xlvi.,
pp. 370-384.)

1801. Lamaeck, J. B. :

Systeme des Animaux sans Vertebres. Paris.

1802. Bosc, L. :

Histoire naturelle des Vers. Suites a Buffon. Castel, Paris.

1816. Lamoueoux, J. V. F. :

Histoire generale des Polypiers coralligenes flexibles. Caen.

1817. Cuviee, G. 0. L. D. :

Regne animale, iv.

1817. Lesueue, C. A. :

Observations on several species of the Genus Actinia. Illustrated by figures. (Journ. Acad.
Nat. Sci. Philadelphia, i., pp. 149, 169, pis. vii., viii.)

1821. Lamoueoux, J. V. F. :

Exposition methodique des genres de l'ordre des polypiers avec leur description et celle des
principales especes figurees dans 84 planches ; les 63 premieres appartenant a' l'histoire
naturelle des Zoophytes d' Ellis et Solander. Paris.

1828. Geay, J. E. :

Spicilegia Zoologica, pis.

664 Haddon and Shackleton — A Revision of the British Actinice.

1830. Lesson, R. P. :

Zoologie. Voyage autour du monde sur la corvette de S. M. la Coquille, pendant les ann^es
1822-1825, par L. J. Duperrey. Paris, 1828, pis.

1832. Delle Chiaje, S. :

Istituzioni d' Anatomia comparata. Napoli, pis., (edition 2, 1836).

1833. Quoy et Gaimard :

Zoologie du Voyage de la corvette 1' Astrolabe, pendant les annees 1826-1829, by G. Dumont
d'Urville. Paris, 1830, pis.

1834. Ehrenberg, C. G. :

Beitrage zur pliysiologischen Kenntniss der Korallenthiere im Allgemeinen und besonders
des Rothen Meeres nebst einem Versuclie zur pliysiologischen Systematik derselben.
(Abhandl. d. Konig. Akad. d. Wissenscb., Berlin, 1832, p. 225.) [Published in 1834,
and also as a separate volume, Die Korallthiere des Rothen Meeres.]

1834. Johnston, G. :

Illustrations in British Zoology. Spongia suberia. (Loudon's Mag. Nat. Hist., vn., p. 491,
fig. 60).

1834. Blainville, H. M. de :

Manuel d' Actinologie ou de Zoophytologie, with Atlas. Paris.

1836. Lamarck, J. B. :

Histoire des Anirnaux sans Vert&bres. [Deshayes and Milne Edwards' revised and augmented
edition.]

1838. Couch, J. :

A Cornish Fauna, being a Compendium of the Natural History of the County. London.

1842. Johnston, G. :

History of British Sponges and Lithophytes, pis. and woodcuts. Edinburgh.

1843. Thompson, W. :

Report on the Fauna of Ireland, div. Invertebrata. (Brit. Assoc. Rep., p. 245.)

1844. Thompson, W. :

Additions to the Fauna of Ireland. (Ann. Mag. Nat. Hist., xin., p. 430.)

1844. Forbes, E. :

Notice of some additions to the British Fauna discovered by Robert Mac Andrew, Esq.,
during the year 1844. (Ann. Mag. Nat. Hist., xrv., p. 415.)

1845. Landsborough, D. :

Notice of some Rarities found on the West Coast of Scotland. (Ann. Mag. Nat. Hist. (1),
xv., p. 327.)

Haddon and Shackleton — A Revision of the British Actinice. 665

1846. Dana, J. D. :

Eeport on Zoophytes, U. S. Explor. Exped., 1838-1842, with Atlas.

1847. Johnston, G. :

A History of British Zoophytes, vol. i., vol. ii, pis., 2nd edit. [The one which is
always used.]

1847. DuBEN, M. W., AND KOREN, J. !

Orn. nogle norske Actinier. (Forhandl. Skan. Naturf. Mode, p. 266.)

1848. DtJBEN, M. W., AND KOEEN, J. \

Ueber einige norwegische Actinien. Isis, p. 536.
1851. Saes, M. :

Beretning om en i Sommeren 1849, foretagen zoologisk Beise i Lofoten og Finmarken. (Nyt
Mag. Naturvid., vi. (2), p. 122.)

1851. Le Conte, J. L. :

Zoological Notes. New species of ... . Zoantha. (Proc. Acad. Nat. Sci. Philadelphia, v.,
p. 320.)

1856. Thompson, W. :

The Natural History of Ireland. (London, 1849-1856, vol. iv., 1856.)

1856. Steenstrup, J. J. S. :

Kongelige Danske Videnskab. Selskabs. Forhandl.

1857. Milne-Edwards, H. :

Histoire naturelle des Coralliaires, ou Polypes proprement dits, i., with atlas. Paris.

1858. Gray, J. E. : ■

On the Dysidea papillosa of Dr. Johnston. (Proc. Zool. Soc, 1858, p. 531, pi. x., fig. 8,
of separate vol., " Badiata "). [Sidisia barleei, g. and sp. nn.]

1858. Holdsworth, E. W. H. :

On Zoanthus couchii, Johnston. (Proc. Zool. Soc, 1858, p. 557, pi. x., figs. 3-7.)

1858. Wright, E. P., and Greene, J. E. :

Eeport on the Marine Fauna of the South and West Coasts of Ireland. (Brit. Assoc. Eep.,
p. 176.)

1858. Gray, J. E. :

Note on Dysidea papillosa, Johnston. (Ann. Mag. Nat. Hist. (3), n., p. 489.)

1859. Danielssen, D. C. :

Beretning om en zoologisk Eeise foretagen i Sommeren 1857. (Nyt Mag. Naturvid., xi
(1861), p. 1.)

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART XII. 5 B

666 Haddon and Shackleton — A Revision of the British Actiniae.

1859. Holdsworth, E. W. H. :

On Zoanthus couchii, Johnston. (Ann. Mag. Nat. Hist. (3), iv., p. 152.)

1860. Sars, M. :

Oplysninger om nogle Ccelenterater fra Norges Kyster. (Forhandl. Skand. Naturf. Mode.

Kjobenhavn, m, p. 690.)
Om nogle nye eller lidet bekjendte norske Coelenterater. (Forhandl. Vidensk. Selsk. Christ.)

1860. Gosse, P. H. :

Actinologia Britannica : A History of the British Sea Anemones and Corals. London.
[Part xi., pp. 321-352, which contains the Zoanthese, was published in Nov., 1859.]

1860. DUCHASSAING, P., ET MlCHELOTTI, J. :

Memoire sur les Coralliaires des Antilles. (Mem. Eeale Accad. Sci., Turin (2), xrx. (1861),
p. 279, pis.)

1861. Holdsworth, E. W. H. :

On an Undescribed species of British Zoanthus. (Proc. Zool. Soc, 1861, p. 99 ; also in
Ann. Mag. Nat. Hist. (3), vn., p. 484, fig.) \Z. rubricornis, n. sp.]

1861. Hincks, T. :

Catalogue of the Zoophytes of South Devon and South Cornwall. (Ann. Mag. Nat. Hist. (8)
vni., p. 364.)

1862. Alder, J. :

Supplement to a Catalogue of the Zoophytes of Northumberland and Durham. Trans.
Tyneside Nat. Field Club, v., pt. iii.) [Vol. v. runs from 1861-1863.]

1862. Schmidt, 0. :

Spongien des Adriatischen Meeres. Leipzig, pis.

1864. Verrill, A. E. :

Eevision of the Polypi of the Eastern Coast of the United States. (Mem. Boston Soc.
Nat. Hist., i. (read 1862, published 1864), p. 1, pis.)

1866. Verrill , A. E. :

On the Polyps and Echinoderms of New England. (Proc. Boston Soc. Nat. Hist., x.,
p. 333.)

1866. DUCHASSAING, P., ET MlCHELOTTI, J. '.

Supplement au Memoire sur les Coralliaires des Antilles. (Mem. Eeale Accad. Sci., Turin (2)
xxin., p. 97, pis.)

1867. Bowerbank, J. S. :

Additional Observations on Hyalonema mirabile. (Proc. Zool. Soc, p. 350.)

Haddon and Shackleton — A Revision of the British Actinice. 667

1867. Gray, J. E. :

Notes on the Zoanthina?, with Descriptions of some New Genera. (Proc. Zool. Soc, 1867,
p. 233, woodcut.) [Brit. sp. referred to — Zoanthus alderi ; Sidisia barleei ; Epizoantbus,
n. g. ; E. papillosus ; Gemmaria (?) sulcata ; Carolia, n. g. ; C. couchii.'j

1868. Heller, C. :

Die Zoophyten und Echinodermen des Adriatischen Meeres. (Ber. k. zool. bot. Gesellsch.,
Wien.)

1868. Norman, A. M. :

Last Beport on Dredging among the Shetland Isles. (Brit. Assoc. Rep., p. 232.)

1869. Verrill, A. E. :

Notes on Badiata. Review of the Corals and Polyps of the West Coast of America. (Trans.
Connect. Acad., i., 1867-1871, p. 377 (p. 495, Mar., 1869).)

1872. Dana, J. D. :

Corals and Coral Islands.

1873. Verrill, A. E. :

Report upon the Invertebrate Animals of Vineyard Sound and the Adjacent Waters, with an
Account of the Physical Characters of the Region, iv., 5, Fauna of the Muddy Bottoms
off the open Coast. (Report of the United States Commissioner of Fish and Fisheries,
1873, pp. 295-747, pis. i. to xxxvm.)

1874. Fischer, P. :

Sur les Actinies des cotes oceaniques de France., (Comptes rendus, lxxxix., p. 1207 ;
translated in Ann. Mag. Nat. Hist. (4), xv., 1875, p. 373.)

1874. Fischer, P. :

Recherches sur les Actinies des cotes oceaniques de France. (Nouv. Arch, du Museum,
Paris, x., p. 193.) [The title page of the vol. gives 1874, but Dr. Fischer (1887) and
other authors give the date as 1875.]

1874. Smith, S. J., and Harger, 0. :

Report on the Dredgings in the Region of St. George's Banks in 1872. (Trans. Connect. Acad.,
ni., p. 1, pis.)

1875. Martens, E. von:

Ueber Palythoa. (Sitzungesber. Gesell. Naturf. Freunde. Berlin, p. 21.)

1875. Fischer, P. :

Anthozoaires du d£partement de la Gironde et des cotes du sud-ouest de la France. (Actes
Soc. linn. Bordeaux, xxx., p. 183.)

1877. Andres, A. :

On a New Genus and Species of Zoanthina malacodermata [Panceria spongiosa, sp. n.]
(Quart. Journ. Micr. Sci. (N. S.), 1877, p. 221 pi. xvi.)

5 B 2

668 Haddon and Shackleton — A Revision of the British Actinias.

1877. Klunzinger, C. E. :

Die Korallthiere des Bothen Meeres, i. Alcyonarien und Malacodermen. Berlin.

1878. Studer, T. :

Zweite abtheilung der Anthozoa polyactinia, welche wahrend der Eeise S. M. S. Corvette
Gazelle um die Erde gesammelt werden. (Monatsber. Konigl. preuss. Akad. Wissensch.
Berlin, p. 524, pi.)

1880. Koch, G. von :

Notizen iiber Korallen. (Morpb. Jabrb., vi., p. 355, pi. xvi.)

1880. Jourdan, E. :

Bechercbes zoologiques et bistologiques sur les Zoantbaires du Golfe de Marseille. (Ann.
des Sci. Nat. (6), x., p. 1.)

1882 : Verrill, A. E. :

Notice of the remarkable Marine Fauna occupying the outer banks of the Southern Coast of
New England, No. 3. (Am. Journ. Sci. (3), xxiii., p. 135 ; ibid., No. 5, p. 309.)

1882. Hertwig, B. :

Beport on the Actiniaria dredged by H. M. S. "Challenger" during the years 1873-187G.
(The Zoology of the Voyage of H. M. S. " Challenger," pt. xv., 1882, pis. Supplement,
1888, pis.)

1882. Marion, A. F. :

Actiniaires atlantiques des dragages de l'aviso le Travailleur. (Compt. rend., xciv., p. 458;
translated in Ann. Mag. Nat. Hist. (5), rx., p. 334.)

1883. Verrill, A. E. :

Beport on Anthozoa and on some additional Species dredged by the " Blake," in 1877-1879,
and by U. S. Fish Commission Steamer " Fish Hawk " in 1880-1882. (Bull. Mus.
Comp. Zool. Cambridge, Mass., xi., 1883-1885.)

1883. Muller, G. :

Zur Morphologie der Scheidewande bei einigen Palythoa und Zoanthus. Marburg. [Disser-
tation for Doctor's degree privately printed.]

1884. Carus, J. V. :

Prodromus Faunaa Mediterranean. Stuttgart.

1884. Andres, A. :

Le Attinie. (Fauna u. Flora d. Golfes v. Neapel, ix. Leipzig.) [Published in the Atti. E.
Accad. dei Lincei, Borne (3a), xiv., 1883.]

1884. Verrill, A. E. :

Notice of the remarkable Marine Fauna occupying the outer banks off the Southern Coast of
New England, and of some additions to the Fauna of Vineyard Sound. (Am. Fish. Com.
Eep. for 1882, p. 641.) [Partial reprint of Verrill, 1882.]

Haddon and Shackleton — A Revision of the British Actinia;. 669
1885. Verrill, A. E. :

Eesults of the Explorations made by the steamer " Albatross " off the Northern Coast of the
United States in 1883. (U. S. Fish. Commission Eeport for 1883, p. 503, pis.)

1885. Pennington, A. S. :

British Zoophytes : an Introduction to the Hydroida, Actinozoa, and Polyzoa found in Great
Britain, Ireland, and the Channel Islands ; with plates. London.

1885. Erdmann, A. :

Ueber einige neue Zoantheen. Ein Beitrag zur anatomischen und systematischen Kenntniss
der Actinien. (Jenaische Zeitschr. Naturwiss., xrx., p. 430, pis.)

1886. Koch, W. :

Neue Anthozoen aus dem Golf von Guinea. Marburg, 36 pp., 5 pis.

1886. Ridley, S. 0. :

Zoanthidae — First Eeport on the Marine Fauna of the South-West of Ireland. (Proc. Roy.
Irish Acad. (2), iv., Sci., p. 599.)

1887. Fischer, P. :

Contribution a l'Actinologie francaise. (Arch. Zool. exp. et. gen. (2), v., p. 381.)

1888. Hertwig, E. :

Supplementary Eeport. (See 1882.)

1889. Haddon, A. C. :

A Bevision of the British Actinias, pt. i. (Trans. Eoy. Dubl. Soc. (2), iv., p. 297, pis.)

1889. Fischer, P. :

Nouvelle contribution a l'Actinologie francaise : le partie, Actinies d'Arcachon ; 2e partie,
Actinies de Guethray. (Actes. Soc. linn. Bordeaux, xliii., p. 252.)

1889. M°Murrich, J. Playfair :

A Contribution to the Actinology of the Bermudas. (Proc. Acad. Nat. Sci., Philadelphia,
p. 102, pis. vi., vn.)

1889 a. McMurrich, J. Playfair :

The Actiniaria of the Bahama Islands, W. I. (Journal of Morphology, in., p. 1, pis. i.-iv.)
[The latter Paper was written before the former, though it was published slightly
subsequently to it.]

1890. Danielssen, D. C. :

Aetinidse. (The Norwegian North Atlantic Expedition, 1876-1878. Zoology, pis.)

1890. Bourne, G. C. :

Eeport of a Trawling Cruise in H. M. S. "Besearch" off the South-West of Ireland.
(Journal Marine Biological Association (Plymouth), i., p. 306.)

670 Haddon and Shackleton — A Revision of the British Actinice.

1890. Joukdan, E. :

Note preliminaire sur les Zoanthaires provenant des Campagnes du Yacht 1' Hirondelle, 1886-
1888. (Bull. Soc. Zool. Paris, xv. p. 174.)

1890. Beneden, E. Van :

Les Anthozoaires pelagiques recueillis par M. le Prof. Hensen dans son Exped. du Plankton.
1. Une Larve voisine de la Larve de Semper. (Bull. Acad. roy. Belgique (3), xx.,
p. 55, pi.)

1891. M°Mukkich, J. Playfatb:

Contributions on the Morphology of the Actinozoa. nr. The Phylogeny of the Actinozoa.
(Journal of Morphology, v., pp. 125-164, pi. ix.)

1891. Haddon, A. C, and Shackleton, A. M. :

Actinia. — I. Zoantheee. Eeports on the Zoological Collections made in Torres Straits
by A. C. Haddon. 1888-1889. (Trans. Boy. Dubl. Soc, vol. iv., ser. ii., pt. xn.)

Haddon and Shackleton — A Revision of the British Actinice.

671

INDEX OF GENERA AND SPECIES.

CAROLIA = EPIZOANTHUS, 634.
couchii, 645.

COKTICIFEKA = PALYTHOA.
lutea, 631.

DYSIDEA = EPIZOANTHUS, 634.
papillosa, 634, 636, 645.

EKDEITHOA (? genus),
rubricornis, 652.

EPIZOANTHUS, 632, 634.

abyssorum, 633, 638, 639.
americanus, 615, 632, 636, 638, 639, 640.
arenaceus, 619, 632, 637, 639, 649.
cancrisocius, 632, 633, 636.
couchii, 616, 618, 619, 632, 635, 637, 644,
645, 646, 647, 649, 653, 661.

yar. linearis, 645.

elongatus, 633.

erdmanni, 623, 633, 635, 639.
eupaguri, 633.

incrustatus, 615, 616, 618, 619, 622, 627,

632, 634, 635, 636, 639, 648.
macintoshi, 615, 625, 633, 635, 649, 650,

651.

norvegicus, 614, 632, 650, 651.
paguriphilus, 611, 614, 615, 616, 620, 622,

633, 635, 641, 643.
papillosus, 632, 634, 636.
parasiticus, 633.
stellaris, 633.
thalamophilus, 633.

wrightii, 614, 615, 616, 633, 635, 651.

GEMMARIA, 630.

isolata, 621, 627, 630.

macmurrichi, 614, 616, 617, 630, 643.

mutuki, 617, 630.

pbilippinensis, 630.

rusei, 621, 626, 627, 630.

sulcata, 660 (? genus).

ISAURUS, 630.

asymmetricus, 616, 617, 618, 621, 622, 623,

630.
cliftoni, 630.
spongiosus, 630.

tuberculatus, 617, 621, 623, 626, 630.

MAMMILLIFERA, 630, 634.

auricula, 626, 630.
conferta, 629 (=Zoanthus confertus).
incrustata, 636 (= Epizoanthus incrustatus).
nymphsea, 630.

tuberculata, 617, 621, 623 (= Isaurus tuber-
culatus).

MAEDCELL = EPIZOANTHUS.

erdmanni, 623, 635.

PALYTHOA, 631, 634.
aggregata, 631.

anguicoma, 656 (Parazoantbus).

arenacea, 636, 645, 649 (= Epizoanthus

arenaceus).
argus, 631.

axinellse, 617, 654 (Parazoantbus).
calcaria, 631.
caribaeorum, 631.
cinerea, 631.

672

Haddon and Shackleton — A

Revision of the British Actinice.

PALYTHOA — {continued).
ccesia, 631.
coesia ?, 619, 631.
coucliii, 645 (Epizoanthus).
flava, 631.
flavo-viridis, 631.
glareola, 631.
glutinosa, 631.

howesii, 617, 618, 622, 623, 625, 631.
kochii, 617, 618, 622, 623, 631.
lutea, 631.

mammillosa, 626, 631, 653.
occllata, 631.
sulcata, 660 (? genus),
tuberculosa, 631.
sp., 656.

PARAZOANTHUS, 633, 653.

anguicoma, 615, 616, 617, 619, 621, 622,
633, 653, 654, 656, 657, 659, 660.

axinelte, 611, 615, 617, 620, 622, 627, 633,
653, 654, 655, 657.

dichroicus, 615, 617, 619, 622, 625, 633.

dixoni, 614, 615, 616, 617, 619, 620, 621,
622, 633, 653, 654, 658.

douglasi, 615, 617, 619, 624, 625, 633.

hertwigi, 616, 633, 657.

sp., 633.

POLYTHOA = PALYTHOA (pars), and PABA-
ZOANTHUS (pars), 634.

anguicoma, 656 (Parazoanthus).

arenacea, 636, 645, 649 (= Epizoanthus

arenaceus).
axinellse, 654 (Parazoanthus).
incrustata, 636.
rubricornis, 652 (? genus),
sulcata, 660 (? genus).

PHYZANTHIJS (? genus),
alderi, 662.

SIDISIA = EPIZOANTHUS, 634.
barleei, 632, 634, 636, 638.

SPHENOPUS, 632.

arenaceus, 632.

marsupialis, 626, 632 ; var. bursiformis, 632
pedunculatus, 632.

SPONGIA = EPIZOANTHUS, 634.
suberia, 636.

T^IKEOTHOA (? genus),
sulcata, 660.

ZOANTHUS, 629, 634.

alderi, 662 (? genus),
anguicoma, 656 (Parazoanthus).
axinellEe, 654 (Parazoanthus).
coppingeri, 616, 618, 621, 622, 623, 629

643, 657, 660.
confertus, 629.

couchii, 636, 637, 638, 644, 646 (Epi

zoanthus).
dame (?), 616, 620, 623, 629.
danai, 629.

nos-marinus, 621, 622, 629.
incrustatus, 636, 638 (Epizoanthus).
jukesii, 616, 618, 620, 621, 623, 629.
macgillivrayi, 618, 620, 621, 622, 623, 625

629, 656.
paguriphilus, 641 (Epizoanthus).
rubricornis, 652 (? genus),
sociatus, 621, 626, 629.
sulcatus, 656, 657, 660 (? genus),
sp., 623, 629.

EXPLANATION OF PLATE LVIII.

TRANS. EOT. DUB. SOC, N.S. VOL. IV., PART XII.

PLATE LVIII.

Fig.

1-22. Epizoanthus incrustatus (Dub. & Kor.), (p. 636).

1-11. Free variety from Shetland; Mus. Normani — 1, simple form, with two polyps ; 2-4,
5-8, 9-1 1, three varietal series.

12-13. Typical incrusting forms from Shetland ; Mus. Normani.

14-21. Incrusting forms from Galway Bay. These are rather smaller and darker than the
more usual forms. This series, starting from a single polyp, illustrates the
manner in which new polyps arise.

22. Antero-postcrior section of a carcinsecium, to show the position of the polyps and the
absence of a ventral polyp.

All the above are drawn from spirit specimens, and are natural size.

23-25. Epizoanthus paguriphilus, Verr. (p. 641).

23-24. Upper and under surface of two different specimens from off S.-W. Irelaud; half
natural size.

25. Young specimen from W. of Ireland; natural size; p.p. posterior polyp.

26-28. Epizoanthus couchii (Johnst.), (p. 644).

26. Living specimen from Berehaven ; drawn by A. C. H.
27-28. Spirit specimens from S.-W. Ireland ; all natural size.

29. Epizoanthus macintoshi, n. sp. (p. 649).

Spirit specimen from Shetland ; natural size.

30-33. Epizoanthus wrightii, n. sp. (p. 651).

30-32. Living specimens from Dublin Bay ; drawn by Mr. G. Y. Dixon ; not to scale.
32 showing larvae swimming inside the tentacles.

33. Spirit specimen ; natural size.

34-36. Parazoanthus anguicoma (Norm.), (p. 656).

34. Some of the original type specimens, consisting of one isolated example, and a group

of four polyps on a sponge, from Shetland (the specimen has unfortunately dried
up) ; Mus. Normani.

35. Ordinary forms from S.-W. Ireland, on the tube of a Serpula.

36. Button-like variety, on the tube of a Hyaloncecia; both natural size, from spirit

specimens.

37-38. Parazoanthus dixoni, n. sp. (p. 658).

37. Group of living specimens from S.-W. Ireland ; tall variety ; drawn by A. C. H.

38. Short variety ; spirit specimens all natural size.

[All the above specimens arc in the British Museum, excepting Nos. 1-13 and 34. No. 29 was
presented by Prof. W. C. M'Intosh, and No. 33 by Mr. G. Y. Dixon.]

Trans. R.Dub. S.N.S .Vol .IV.

Plate LVII1.

ME Parker deletlrtk.

West.Newman unjj.

EXPLANATION OF PLATE LIX.

TEANS. HOY. DUB. SOC, N.8. VOL IV., PART XII.

PLATE L I X.

LETTERING ADOPTED IN THE FIGURES.

. cuticle.

/.

. ectoderm.

incr.

ect. can , . .

. ectodermal canal.

enc. sin., .

. encircling sinus.

mes.,

. endoderm.

nem.

end. can.,

. endodermal canal .

p. b.

fibrilla.

parieto-basilar musi le.

Fig.

2

1. Epizoanthus macintoshi, n. sp. (p. 649). Transverse section through the body-wall, — .*

. 2

2. Epizoanthus incrustatus (Dub. & Kor.), (p. 636). Transverse section through the body-wall,

v If

2

3. JEpizoanthus wrightii, n. sp. (p. 651). Transverse section through the body-wall, — .

2

4. Epizoanthus couchii (Johnst.), (p. 644). Transverse section through the body-wall, — .

2

5. Epizoanthus norvegicus (Kor. & Dan.), (p. 650). Transverse section through the body-wall, —

2

6. Epizoanthus paguriphilus, Verr. (p. 641). Transverse section through the body-wall, — .

/{

2

7. Epizoanthus arenaoeus (D. Ch.), (p. 649). Transverse section through the body-wall,

2

8. Parazoanthus axinella (Schmidt), (p. 654). Transverse section through the body-wall, .

2

9. Parazoanthus dixoni, n. sp. (p. 658). Vertical section through the body-wall, — .

2

10. Parazoanthus dixoni. Transverse section through the body -wall, -j-.

2

11. Parazoanthus anguieoma (Norm.), (p. 656). Transverse section through the body-wall, — .

2

12. Parazoanthus anguieoma. Vertical section through the body-wall, — .

x>

* These letters of magnification refer in all cases to Zeiss' system.

Trans. R.Dub. S.,N.S.,Vol. IV. Plate LIX

M P Parker cfhrliti.

EXPLANATION OF PLATE LX.

PLATE LX.

LETTERING ADOPTED IN THE FIGURES.

. cuticle.

nem.,

. ncmatocyst.

. ectoderm.

. oesophagus.

enc. sin.,

. encircling sinus.

oesophageal ridge.

end

. endoderm.

p. b. m.,

. parieto-basilar muscle.

end. sph. m.,

endodermal sphincter muscle.

r. eet., . .

. reflected ectoderm.

. incrustation.

r. end., .

. reflected endoderm.

. mesoglcea.

r. m.,

. retractor muscle.

m. cn. mes.,

macrocnemic mesentery (the sulco-

s. a.,

. sulcar directive mesenteries.

sulcar lateral mesentery).

. sulcular directive mesenteries.

>»./., . .

mesenterial filament.

s. gr.,

. sulcar groove.

m. sph. m., .

. mesoglceal sphincter muscle.

. sperm-cell (testis).

Fig.

1. Epizoanthus incrustatus (Dub. & Kor.), p. 636). Transverse section through the oesophageal region

4

of the column,

a* 10'

2

2. Epi%oanthus wrightii, n. sp. (p. 651). Vertical section through the sphincter muscle,

2

3. Epi%o(inthus couchii (Johnst.), (p. 644). Vertical section through the sphincter muscle, — .

H

2

4. Epizoanthus arenaceus (D. Ch.), (p. 649). Vertical section through the sphincter muscle, — .

4

5. Epizoanthus paguriphilus, Verr. (p. 641). Transverse section through a fertile mesentery, # .

6. Parazoanthus axinella (Schmidt), (p. 654). Transverse section through the oesophageal region of the
4

column, —

a* 10

2

7. Parazoanthus axinellce. Transverse section through a fertile mesentery, — .

2

8. Parazoanthus dixoni, n. sp. Cp. 658). Vertical section through the sphincter muscle, — .

2

9. Parazoanthus dixoni. Transverse section through a perfect and an imperfect mesentery, —

* These letters of magnification refer in all cases to Zeiss' system.

Trans.R.Dub. S.,N.S.,Vol.lV.

West.Newiruui imp.

[ 673 ]

XIII.

EEPOETS ON THE ZOOLOGICAL COLLECTIONS MADE IN TOBBES STEAITS
BY PEOEESSOE A. C. HADDON, 1888-1889.

ACTINIA: I. ZOANTHEiE. By PEOEESSOE ALFEED C. HADDON, MA. (Cantab.),
M.E.I. A., Professor of Zoology, Eoyal College of Science, Dublin, and MISS ALICE
M. SHACKLETON, B.A. Plates LXL, LXIL, LXTIL, LXIV.

[Read November 19, 1890.]

The following is the first instalment of an investigation on the structure and
systematic relations of the Actiniae collected by one of us in Torres Straits. We
decided to publish our account of the Zoantheae first, as it is a well circumscribed
group and admits of independent treatment. We took this opportunity of studying
the British forms, and have thus had a considerable number of forms under exami-
nation at the same time. This has given us a personal knowledge of every genus
except Mamroilifera, of which genus no authentic specimens exist in any museum.

Our account of the British Zoanthese is simultaneously published with this as
" A Revision of the British Actiniae," Part II. : The Zoanthese (Trans. Royal Dublin
Society, vol. iv., ser. n.) ; and we would refer the reader to that Memoir for a general
summary of the anatomy of the group, and a special account of that of the British
representatives. We have also given a classification of the Zoantheae, and as far
as is possible have allocated all the species described by other authors to their
proper genera. It is impossible at the present time to monograph this group, as
there is such a general sameness in external character that it makes it difficult to
seize on points which are of descriptive value. The present confusion in which
this group lies is mainly due to this fact ; the fault is that of the animals themselves
rather than that of the zoologists who have described and named them. This
similarity of appearance not only affects the species of a genus, but also the species
of different genera. Thus it becomes a necessity for every species to be examined
anatomically by means of microscopical sections, first to determine its genus, and
secondly to discover accurate specific characters. Once a species is thoroughly

TRANS. ROY. DUB. SOC, U.S. VOL. IV., PART Xllt. 5 E

674 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

known it will generally be possible to identify other specimens belonging to that
species by external characters only. Owing to the incrusted nature of most of the
Zoanthese it is very difficult to get satisfactory sections, and for the same reason
spirit specimens are often apt to be badly preserved for histological purposes.

It is not unfair to point out that the disorder which has occurred in this group
is also partially due to the fact that many zoologists have not paid due regard to
the generally recognised rules of zoological nomenclature, and have not taken the
trouble to thrash out the synonymy ; and some have identified certain forms with
pre-existing species in a rather reckless manner.

Owing to the lack of salient external characters, which could be observed in
preserved specimens, we have not been able to give diagnostic names to most of
the species, and we have consequently associated them with the names of zoologists
who have collected in Torres Straits, or who have studied the group. The types
of the species have been given to the British Museum, in which institution will
also be found a complete set of slides illustrating the anatomy of all the forms
described in this and in the preceding Memoir.

CLASSIFICATION OF THE GEOUP.

ZOANTHEiE.

Actinise with numerous perfect and imperfect mesenteries, and two pairs of
directive mesenteries, of which the sulcar are perfect and the sulcular are imperfect.
A pair of mesenteries occur on each side of the sulcular directives, of which the
sulcular moiety is perfect and its sulcar complement is imperfect ; a similar second
pair occurs in one section of the group (Brachycneminae), or the second pair may
be composed of two perfect mesenteries (Macrocnerninse). In the remaining pairs
of mesenteries, of both divisions, this order is reversed, so that the perfect mesentery
is sulcar and the imperfect is sulcular. The latter series of mesenteries are bilateral
as regards the polyp, and arise independently (i.e. neither in pairs nor symmetri-
cally on each side) in the exoccele on each side of the sulcar directives, in such a
manner that the sulcular are the oldest, and the sulcar the youngest. Only the
perfect mesenteries are fertile, or bear mesenterial filaments. A single sulcar
oesophageal groove is present ; the mesoglcea of the body-wall is traversed by
irregularly branching ectodermal canals, or by scattered groups of cells ; the body-
wall is usually incrusted with foreign particles. The polyps are generally grouped
in colonies connected by a ccenenchyme, the ccelenteron of each polyp communicat-
ing with that of the other members of the colony by means of basal endodermal
canals.

Haddon and Shackleton — Actinice : I. Zoanthece.

675

Family. * ZOANTHIDJE, Dana, 1846.

(With the definition of the group.)

Sub-family. Brachycnemin^e, Hadd. & Shackl., 189 L.

Zoanthese in which the sulcar element of the primitive sulco-lateral pair of
mesenteries (cnemes) is imperfect : —

GENEEA OF THE BBACHYCNEMINiE .

Zoanthus, Lamarck, 1801.

Isaurus, Gray, 1828.

( ? Mammillifera, Lesueur, 1817. (Not represented in

Torres Straits). )

Gemmaria, Duchassaing et Michelotti, 1860.

Palythoa, Lamouroux, 1816.

Sphenopus, Steenstrup, 1856.

Sub-family. Macrocnemin^e, Hadd. & Shackl., 1891.

Zoanthese in which the sulcar element of the primitive sulco-lateral pair of
mesenteries (cnemes) is perfect : —

GENEEA OF THE MACEOCNEMIN^.

Epizoanthus, Gray, 1867. (Not represented in Torres

Straits).

Parazoanthus, Haddon & Shackleton, 1891.

Sub-family. Brachycnemin^e.

ZOANTHUS, Lamarck, 1801.

Zoanthus, Cuvier, 1817.

Zoanthus (Rhyzanthus), Andres, 1884.

Brachycnemic Zoanthese with a double mesoglceal sphincter muscle. The
body-wall is unincrusted ; the ectoderm is usually discontinuous ; a well developed
ectodermal canal system in the mesogloea. Dioecious or monoecious. Polyps
connected by a thin ccenenchyme.

5 E 2

676 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

Cuvier (1798) was the first to recognise some distinction between the Zoanthese
and other Actiniae, but in an indefinite sort of way; he refers to " 1. Le zoanthe
k cinq p^tales (Actin. dianthus)', 2. Le zoanthe a drageons (Actin. sociata)."

Lamarck (Systeme, 1801) first divided the Actinse into the genera Actinia and
Zoantha; he says (1801, p. 363): " II6. genre. Zoanthe, Zoantha — Zoantha sociata,
Act. sociata, Sol. et Ellis, Hydra sociata, Gmel."

Bosc (1802, p. 261) refers to " Zoanthe, Zoantha, Lam. ; Z. ellisii; Hydra sociata ;
Act. sociata, S. & Ell."

Cuvier, in 1817 (p. 53), speaks of Zoanthus sociatus.

In Deshayes and Milne-Edwards' revised and augmented edition of Lamarck's
Hist, des anim. sans vert. (1836, 2nd ed., p. 77), three species are acknowledged:
"Zoanthe (Zoantha). — 1. Zoantha ellisii, Bosc (Act. sociata, etc.); 2. Zoantha
solanderi, Les. ; 3. Zoantha bertholetii, Ehr."

Dana is the only later author who adheres to Zoantha instead of Zoanthus.
According to the generally accepted rules of zoological nomenclature the Greek
avOos would have to be written anthus, it being agreed that, " in writing zoologi-
cal names, the rules of Latin orthography must be adhered to."

TORRES STRAITS SPECIES OF THE GENUS ZOANTHUS.

Z. coppingeri, n. sp.

Z. jukesii, n. sp.

Z. macgillivrayi, n. sp.

Zoanthus coppingeri, n. sp.
(PI. lxi., figs. 1, 2 ; PL lxii., fig. 1 ; PI. lxiv., figs. 1-4.)

Form. — Body smooth, pyriform when contracted, rather elongated when ex-
panded. Polyps in clusters, the buds springing from the bases of the polyps
themselves ; ccenenchyme, thin, encrusting. Tentacles, in two rows, similar.

Colour. — Pinkish below, greenish or bright green above, sometimes entirely
pinkish ; always with brown streak-like spots ; disc, burnt sienna, with darker spots ;
rim of mouth, brown ; tentacles, gray, with a single row of black spots ; there is a
black spot between each tentacle, and these are continued as black lines on the
capitulum.

Dimensions. — Length of a contracted specimen, 15 mm. ; diameter of upper
portion, 5 mm.

Locality. — Fringing Reef, Mabuiag. Oct. 19, 1888. Numerous specimens.

Haddon and Shackleton — Actinice : I. Zoanthece.

677

We have named this species in honour of Dr. Coppinger, who, when surgeon on
board H.M.S. " Alert," collected some marine zoological specimens from Torres
Straits.*

Bocly-ivall (Pis. lxii., lxiv.). — The wall of the column is bounded exter-
nally by a distinct cuticle. Between this cuticle and the ectoderm lies a thin
peripheral layer of mesogloea, the " subcuticula" of Andres and McMurrich. The
ectoderm forms an almost continuous layer, but is crossed by numerous delicate
strands of mesoglcea, which unite to form the peripheral layer. In addition to the
ordinary columnar cells, nematocysts of an oval shape are present. Numerous
branching and anastomosing canals arise from the ectoderm, and run through the
mesoglcea, generally in a radial direction. They vary greatly in size. Sometimes
they run along close to the endoderm, but we have never observed any connexion
with it. Many of these canals pass into the mesenteries, where they form large
sinuses. Nematocysts, similar to those in the ectoderm, are found in these canals.
The mesoglcea, which constitutes the chief thickness of the body-wall, is homoge-
neous and clear, and is permeated by the usual minute cells, which are drawn
into fine protoplasmic strands. These have a radial direction, and extend right
across the mesoglcea, from endoderm to ectoderm. The endoderm is crowded
with zooxanthellae. There is a slight diffuse endodermal muscle.

Capitulum. — The ectoderm becomes continuous in the capitulum, and in
contracted specimens is thrown into deep folds. Nematocysts are very
numerous.

Sphincter muscle. — The double sphincter muscle is a powerful one, the upper
portion being slightly shorter than the lower one (PI. lxiv., fig. 3). It consists
of numerous irregularly shaped cavities, the mesogloea being arranged in com-
plicated plaitings.

Tentacles (PI. lxiv., fig. 2). — The ectoderm of the tentacles is normal and
ciliated. The nuclei form a distinct central band in section. Outside the band
are numerous, small, thin nematocysts, whilst between the band of nuclei and the
mesoglcea small irregular cells may be discerned, which are probably nerve cells.
There is a diffuse ectodermal muscular layer. The fibres, which are longitudinal
in direction, are supported on simple plaitings of mesogloea. The mesoglcea
forms a thin layer without canals or enclosures of cells. The endoderm, which is
crowded with zooxanthellse, is very thick, so that the lumen of the tentacles is
almost obliterated. Nematocysts, similar to those found in the capitulum and
other parts of the ectoderm, are abundant in the endoderm of the tentacles. The
endodermal muscle fibres are circular in direction.

* See " Report on the Zoological Collections made in the Indo-Pacific Ocean during the Voyage of
H. M. S. 'Alert,' 1881-1882" (1884).

678 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

Disc. — The structure of the disc is very similar to that of the tentacles, but we
have not found nematocysts in the endoderm of this region.

(Esophagus. — The ectoderm of the oesophagus forms a simple layer. The
groove is visible, although not very well marked. The mesoglcea is extremely
thin, and of uniform thickness.

Mesenteries. — The arrangement of the mesenteries is brachycnemic. They
are coiled and folded, almost entirely rilling up the body-cavity. The ectoderm
of the oesophagus is reflected upwards and continued downwards into the
mesenterial filaments, forming numerous folds along each mesentery (PI. lxiv.,
fig. 4), in a manner which will be more fully described in our account of
Z. macgillivrayi. The mesoglcea is extremely thin in the upper part of the
mesentery, although thicker in the immediate neighbourhood of the wall, where
it usually contains a "basal" canal. Lower down the mesogloea is thicker
throughout, and here the canal expands to form the large sinus, which, as we
have previously mentioned, is connected with the ectodermal canal system of the
body-wall (PI. lxil, fig. 1). The endoderm of the mesenteries forms a deeper
layer than that of the body-wall, and zooxanthellae, though present, are not
nearly so numerous. The nuclei of the columnar cells form a peripheral band,
leaving a clear space next to the mesogloea. Nematocysts are also to be found
in the endoderm of this region. The parieto-basilar muscle is diffuse and
feebly developed. The longitudinal muscle fibres are also very feeble, being
scarcely discernible. There is no special thickening of the endoderm in the lower
part of the mesenterial filaments as in Z. macgillivrayi.

Gonads. — The sexes are distinct. We have sections of both male and female
specimens (PI. lxiv., figs. 3, 4). The gonads appear to be distributed on the
mesenteries in irregular rows.

Zoanthus jukesii, n. sp.
(PI. lxl, figs. 3-5; PI. lxii.j fig. 2 ; PI. lxiii., fig. 1.)

Form. — Body short and thick ; body-wall smooth and delicate ; ccenenchyme
forming stolons : tentacles in two cycles of about 20—24 in each.

Colour. — Body and stolon translucent gray, the endoderm shining through
with a brown tint (owing to the presence of zooxanthellae) ; capitulum pink, with
24 dark lines ; disc brown, with, usually, pairs of pale lines (mesenteries) for
inner cycle of tentacles ; mouth with greenish lip ; oesophagus gray. Tentacles :
inner cycle green, with dark rings or marks on the oral aspect; outer cycle opaque
pale pink ; all the tentacles with a dark spot at the tip ; the base of the tentacles
of the outer cycle is in some specimens tinged with green.

Haddon and Shackleton — Actinice : I. Zoanthece.

679

Dimensions. — Height 7-12 mm. ; diameter of disc, 6 mm.

Locality. — Fringing Reef, Mer (Murray Islands), Jan. 29, 1889. Numerous
specimens.

We associate this species with the name of the late Prof. Beete J ukes, at one
time Professor of Geology in the Royal College of Science, Dublin, who was also the
author of the interesting Voyage of the "Fly."* To this day the name of this
genial naturalist is still remembered in the Murray Islands and in Erub.

Body-tvall (PI. lxil, fig. 2). — A cuticle and peripheral mesogloea are present
as in Z. coppingeri. The cells of the ectoderm are not distinct but appear to have
become fused, as in the specimen of Z. sodatus, described by M°Murrich (1889a,
p. 63). For the most part they appear to form a quite continuous and narrow
layer, but in some parts the contents of the cells, adhering closely to the mesogloea
on either side, leave an empty space, across which, irregularly placed and
exceedingly delicate strands of mesogloea are seen to pass. Anastomosing canals,
connected with the ectoderm, are present, though not at all so numerous as in
Z. coppingeri. Lacunae, clearly of similar origin, but completely surrounded by
the mesogloea, are more frequently to be met with. The canals and lacunae are
most abundant in the lower part of the column, and here their connexion with the
basal canals of the mesenteries can be demonstrated (PI. lxii., fig. 2). The
mesogloea is of the usual character. Zooxanthellae also abound in the endoderm of
this species. There is a diffuse endodermal muscular layer, supported by acute
mesogleal prominences.

Capitulum. — The ectoderm of the capitulum is thrown into folds, as in Z. cop-
pingeri, and rather opaque oval cells, with a clear outline (probably nematocysts,
are here very numerous, being generally embedded singly in in the mesogloea.

Sphincter muscle. — The sphincter muscle is not so strongly developed as in
Z. coppingeri. Of the two parts of the muscle the upper one is in this case the
longer. The muscle cavities are larger and less filled up with cells, the plaitings of
the mesogloea being simpler than in Z. coppingeri.

Disc and tentacles. — The ectoderm of the disc and tentacles closely resembles
that described for Z. coppingeri. The endoderm is crowded with zooxanthellae,
but contains no nematocysts.

The ectoderm of the oesophagus is thrown into slight folds. The groove is
well marked (PI. lxiil, fig. 1).

Mesenteries (PI. lxiii., fig. 1). — The arrangement of the mesenteries is of the
usual brachycnemic type. The reflected ectoderm of the oesophagus forms a smaller

* Narrative of the Surveying Yoyage of H. M. S. " Fly," commanded by Captain F. P. Blackwood, R.N.
(during the years 1842-1846). 1847. By J. Beete Jukes.

680 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

number of folds than in the last species described. The mesenterial filaments also
appear shorter in transverse section. The mesogloea is thicker throughout, and
usually contains more than one canal in each mesentery.

These canals appear to run from the base of the mesenteries to the oesophageal
region. Near the base they appear to be connected with ectodermal spaces in
the body- wall. The endoderm of the mesenteries is very similar to that of the
body- wall.

The longitudinal muscles are better developed than in Z. coppingeri, the
mesogloea being thrown into slight plaitings to support the fibres. The parieto-
basal fibres, though distinct, are rarely supported by plaitings.

Gonads. — The sexes appear to be distinct in this species also. All the speci-
mens examined by us containing mature reproductive organs were female. The
gonads are irregularly arranged as in Z. coppingeri.

This species somewhat resembles the preceding one ; spirit specimens can be
distinguished externally by the following characters : — Z. coppingeri is larger ;
markedly pyriform when contracted, and the brown spots persist (for at least
three years).

Zoanthus macgillivrayi, n. sp.

(PL lxl, fig. 6 ; PI. lxii., fig. 3; PI. lxiii., fig. 2 ; PI. lxiv., figs. 5-8).

Form. — Body smooth, transversely wrinkled, with a thick cuticle, upper part of
column slightly swollen, disc large ; tentacles small, 32 in number, in two cycles ;
mouth very small. The capitulum in expanded specimens exhibits two encircling
grooves, which indicate the double sphincter muscle, ccenenchyme forming a
flattened stolon.

Colour. — Not determined when alive ; yellowish in alcohol.

Dimensions. — Height of large specimens, 18 mm. ; average diameter of colour,
3 mm. ; diameter of disc, 6.5 mm.

Locality. — Fringing reef, Mabuiag, Sept. 21, 1888. Six specimens.

We acknowledge in the specific name we have given to this species the
zoological labours in Australasia of the late J. Macgillivray, author of the valuable
"Voyage of the Rattlesnake."*

Body-wall. — The wall of the upper part of the column is comparatively thin.
Lower down it is much thicker. The cuticle is thick, and foreign bodies,

* Narrative of the Yoyage of H. M. S. "Rattlesnake," commanded by the late Captain Owen Stanley,
B.N., F.R.S., during the years 1846-1850 (1852).

Haddon and Shackleton — Actinia) : I. Zoanthece.

681

foraminifera, diatoms, &c, are occasionally to be found embedded in it, and in
the peripheral layer of mesogloea. The latter can be very distinctly seen in this
species. As in Z. jukesii the cells of the ectoderm appear to have become fused,
and crossing strands of mesogloea can only be seen in those few places where the
ectodermal space is nearly empty. Anastomosing ectodermal canals, very similar
to those found in Z. coppingeri, run through the mesoglcea and are connected with
the basal canals of the mesenteries near the union of the column with the
ccenenchyme (PL lxii., fig. 3). The surface of the column is thrown into
numerous folds, which appear in cross-section as deep ectodermal bays lined with
cuticle.

Sphincter muscle. — The sphincter muscle is somewhat similar to that in Z.
jukesii, the upper being the longer of the two parts (PI. lxiv., fig. 5). The cavities
are simpler than in Z. coppingeri, but they are not so large as in Z. jukesii.

Disc and tentacles. — The structure of the disc and tentacles is very similar to
that of the preceding species. There are no nematocysts in the endoderm.

(Esophagus. — There is a well marked oesophageal groove.

Mesenteries. — -Of the two specimens which we have cut transversely, one shows
the usual brachycnemic arrangements. In the other there are four imperfect mesen-
teries at the sulcular side of the oesophagus, instead of the usual pair of imperfect
directives. The reflected oesophageal ectoderm and the structure of the
mesenterial filaments can be well studied in this species. As can be seen in a
longitudinal section, such as that figured (PI. lxiv., fig. 5), the ectoderm of the
oesophagus passes continuously on to the mesentery, where it suddenly becomes
greatly thickened, and is thrown into transverse folds, the whole thickening
having a crescentic form, first curving upwards and then downwards, losing itself,
in the mesenterial filament. The ectoderm is reflected on both sides of every one
of the perfect mesenteries, presenting in transverse section a characteristic pinnate
appearance (PI. lxiv., fig. 6). As above mentioned, the reflected ectoderm passes
gradually into the mesenterial filament, the characteristic V shape of the latter
(PI. lxiv., fig. 7) being continuous with the peripheral folds of the former.
The lateral elements of the mesenterial filaments gradually become shorter, so that
as it descends only the median portion is left. Numerous nematocysts are found
in this lower portion of the filament (PI. lxiv., fig. 8). In this species the
mesenterial filaments are confined to the upper part of the column, gradually
disappearing about the middle of the column. As the filaments disappear the
mesenteries also become much narrower (appearing in transverse section to
shorten), projecting but a little way into the ccelenteron (PI. lxiii., fig. 2). Lower
down they again widen and project further, finally uniting in the centre at the
base of the polyps to form the ccelenteric canals of the stolon (PI. lxii., fig. 3).
The mesogloea of the mesenteries is well developed, especially near the base.

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682 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

Canals are present from the oesophageal region downwards, frequently two or
three in the perfect mesenteries. These canals are connected with the canals of
the body-wall at the base of the column. Nematocysts are numerous in the
endoderm of the mesenteries. The longitudinal muscle fibres form a simple
layer, the parieto-basal muscles are better developed and supported upon slightly
branched plaits of mesogloea.

Gonads. — No gonads were present in the specimens we examined.

This species cannot be mistaken for either of the two previously described.

ISAURUS, Gray, 1828.

Antinedia, Duch. & Mich., 1866.
Polythoa (Monothoa) (pars), Andres, 1884.
Zoanthus (Monanthus) (pars), Andres, 1884.

Large brachycnemic Zoantheas with a single mesoglceal sphincter muscle.
The body-wall is unincrusted; the ectoderm discontinuous; ectodermal and
endodermal bays and small canals in the mesogloea. Monoecious or dioecious.
Polyps in small clusters or solitary.

The genus Isaurus was established by J. E. Gray in 1828 (Spic. Zool., 1828,
p. 8) to include a species not before described, specimens of which from an
unknown locality were in the British Museum. He named this species Isaurus
tuberculatus on account of the tubercles on its surface. The name Isaurus is a
Latinized version of Isaure, a name applied by Savigny (Description de l'Egypte,
Polypes, pi. 2, figs. 1—4, 1811, ined.) to four species figured by him in 1811, and
supposed by Gray to be of the same genus as his /. tuberculatus. Savigny published,
however, neither the characters of the genus nor descriptions of the species.
Lamouroux mentions the genus as Isaura, but neither does he define it in any
way.

The genus Isaurus must therefore be regarded as Gray's, and Isaurus tubercu-
latus as the type species.

In 1860 Duchassaing and Michelotti found specimens at St. Thomas and
Guadaloupe, which closely agreed with Gray's account of Isaurus tuberculatus.
Although unaware of the existence of Gray's species, they gave to their specimens
the same specific name, calling them Zoanthus tuberculatus, and subsequently in 1864
(forming for the species a new genus), Antinedia tuberculata. Andres considered
that Gray's /. tuberculatus, and Duchassaing and Michelotti's A. tuberculala, were
distinct species, and consequently renamed the latter A. duchassaingi.

Haddon and Shackleton — Actinice : I. Zoanthece.

683

In 1889 McMurrich described specimens from the Bermudas, evidently belong-
ing to Gray's species and also agreeing closely with A. tuberculaia, Duch. & Mich.,
which he considers to be identical with it. Anatomical examination of these
specimens showed that they possessed most of the characters which Erdmann has
ascribed to the genus Mammillifera. M°Murrich therefore identified his specimens
as Mammillifera tuberculata (Gray).

From Erdmann's Paper, however, we cannot find that he has sufficient reasons
for concluding that the characters attributed by him to Mammillifera are possessed
by any of the species for which that genus was erected by Lesueur in 1817. The
specimens found by Erdmann in the museum at Bonn, from which he deduced
these generic characters, were not referred to any species.

The generic name Mammillifera was adopted in 1817 by Lesueur for two
species from the West Indies, named by him M. auricula and M. nymphcea. His
definition of the genus is "A large cuticular expansion serving as a base for
numerous animals, which, when contracted, assume the form of mammas" (p. 178).
From the dimensions given by Erdmann for his unnamed specimen, it seems
possible that it agrees to some extent with this description, but the same might be
said of Zoanthus julcesii ; whilst both Gray's I. tuberculatus and our /. asymmetricus
entirely disagree with it in outward form. It therefore appears that it is impossible
to determine the true characters of the genus Mammillifera until the type species
M. auricula has been recovered and submitted to anatomical examination. Until
this is done we must therefore retain the name Isaurus for those species which
undoubtedly belong to the same genus as I. tuberculatus and I. asymmetricus.

Although, as above stated, Gray instituted the genus Isaurus for /. tuberculatus,
we find that in 1867 (P. Z. S., p. 234) he erects a new genus, Pales, for a closely
allied form. In his "Solitary, rarely irregularly aggregate" division of the
" Zoanthi malacodermi, or soft-skinned Zoanthi, or Zoanthinae," he recognises
three genera: "Isaurus, Gray, Spic. Zool., 8, 1825 [the copy we have seen is
dated 1828] ? Orinia, Duchassaing and Michelotti, Mem. Coral, des Antilles, 54.
Pales [which he defines thus] — Body cylindrical, isolated, solitary, clustered, or
sometimes proliferous, but each specimen having a separate base ; outer skin
smooth, thin, olive-brown, slightly concentrically wrinkled; the tentacles numerous,
the internal laminae numerous, slender, only slightly elevated, straight and parallel
above, with a thickened edge, and sinuous below. Pales cliftoni (fig. 1, p. 236) —
Hab. Western Australia (Mr. Clifton). The bodies are from i to J- inch in diameter;
but they vary greatly in length, some being as much as 2 inches long ; but the

general length [in spirits] seems to be about an inch They are found

attached to shells, both isolated and in clusters, and the larger ones are attached
to the base of each other, forming a somewhat stellate cluster, as if they were free,
floating in the sea."

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684 Reports on the Zoological Collections made in Torres Straits, 1888—1889.

It seems probable that the two genera are coterminous, and, if so, /. cliftoni
will rank as a second Australian species of Isaurus.

In 1877 Andres described (p. 226) a new genus and species, Panceria spongiosum
from Port Natal; but in 1884 (p. 315) he abandoned the genus, and re-named it
Polythoa (Monothoa) spongiosa. We regard this as belonging to the genus under
discussion.

TORRES STRAITS SPECIES OF THE GENUS ISAURUS.
/. asymmetricus, n. sp.

Isaurus asymmetricus, n. sp.

(PI. lxl, figs. 7-9; PI. lxil, fig. 4 ; PL lxiii., figs. 4-6 ; PI. lxiv., fig. 9.)

Form. — Body elongated; upper portion of column, in retracted specimens,
with usually four rather irregular longitudinal rows of tubercles, arranged in such
a manner that there is a longitudinal area free from them. In some specimens
there are intermediate tubercles, which may even form one or two rows. Young
specimens are entirely smooth. The smooth side is somewhat shorter than the
tuberculated, so that the body bends over to the former, and the introverted
mouth is rarely terminal. The contracted capitulum exhibits radiating furrows
from 18 in number upwards.

The polyps grow either singly or in small clusters. In the latter case there
is a common, firm, fleshy, incrusting ccenenchyme, occasionally forming stolons,
from which new buds arise.

Colour. — Whitish below, passing into brownish above; the darker portion is
variously mottled with cream, or greenish cream, and occasionally diversified with
darker spots ; the tubercles are somewhat pinkish in colour.

Dimensions. — Average size of retracted specimens, 45 mm. in length ; greatest
diameter, 7 mm. The longest specimen measured 56 mm. in length when
retracted.

Locality. — Torres Straits ; on fringing reef between tides, Mabuiag, Oct., 1888,
numerous specimens ; 15—20 fathoms, between reefs, Murray Islands, Jan. 5,
1889, two specimens.

The specific name is derived from the marked asymmetry of the polyp. It is
undoubtedly nearly allied to the Mammillifera tuberculata of M°Murrich
(1889, p. 117). The specific differences are the lesser number and greater size of
the tubercles, though their diameter is about the same, and their asymmetrical ar-
rangement; the height of our species is about double that of the West Indian form.

Haddon and Shackleton — Actinice : I. Zoanthece.

685

Our deeper water specimen was shorter and relatively much more tuberculated.
In the " Special volume of the Proceedings of the Geographical Society of
Australasia" (Sydney, 1885), under a section designated as "New Guinea
Exploration," there is a letter from Dr. J. W. Haacke, concerning a collection of
Anthozoa from Thursday Island, Torres Straits, in which he refers to " a species
belonging probably to a new genus closely allied to the genera Polythoa and
Zoanthus. This genus would be characterized by showing, even externally, a very
obvious bilateral symmetry, better, I believe, than any other An thozoon" (p. 225).
There is no doubt that this is our new species.

We have copied Gray's account of the other Australian representative in our
account of the genus, the absence of tubercles readily distinguishes it from our
species. The same also holds good for the Port Natal species, spongiosa.

Body-wall (PI. lxii., fig. 4). — The thick body-wall is covered by a cuticle as
in the species of Zoanthus described. The ectoderm is not continuous, but is
broken up into fairly uniform groups of cells by well developed strands of
mesoglcea, which connect the peripheral with the general mesoglcea (PI. lxiii.,
fig. 6). Amongst the ordinary columnar cells of the ectoderm are to be found
numerous zooxanthellse, as well as occasional large nematocysts. Bays of
ectoderm, in which the cuticle may to a greater or less extent be involved, often
occur. Canals and lacunae of much smaller diameter than the anastomising canals
which occur in the species of Zoanthus we have described, are also present. Some
of these can be shown to be continuous with the ectoderm, whilst others have an
equally clear connexion with the endoderm (PI. lxiii., fig. 5). Endodermal bays,
which may be quite shallow, or may extend to a greater or less extent into the
mesoglcea as large open canals, are not unfrequent (PI. lxii., fig. 4; PI. lxiv.,
fig. 9). Occasionally these are slightly branched. A few nematocysts, smaller
than those found in the ectoderm, as well as zooxanthellae, are present in the
endoderm. The endodermal muscular layer is well developed.

Sphincter muscle. — The single mesoglceal sphincter muscle is extremely thick
and powerful. The cavities are well filled with muscle cells (PI. lxiii., fig. 4).

CapUulum. — The cuticle and peripheral layer of mesoglcea, as well as the
strands of mesoglcea which break up the ectoderm, are present in that part of
the capitulum, which in contracted specimens is thrown into folds, but the cuticle
disappears, and the ectoderm becomes continuous as the tentacles are approached.

Disc and tentacles. — The usual small nematocysts are found in the outer part of
the ectoderm of the tentacles. The nuclei do not form a distinct central band, but
are diffused, leaving, however, a clear band next to the muscle fibres. The
ectodermal muscular layer is remarkably well developed. The fibres are
supported on fine and complicated mesoglceal plaitings, forming in some cases a
band nearly equal to one-third of the entire thickness of the wall of the tentacle.

686 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

In some places these plaitings appear to unite to form a distinct band of mesoglcea,
outside the muscle fibres, so that here the muscle may be regarded as mesogloeal.
The endodermal muscular layer is well developed, especially at the bases of the
mesenteries, but it is not at all so remarkable as is that of the ectoderm. The
endoderm, as well as mesoglcea, is relatively thin in the tentacles. The endoderm
contains numerous zooxanthellse.

(Esophagus. — The ectoderm of the oesophagus is thrown into slight and irre-
gular folds. The groove is only indicated by a slight depression in the region
of the sulcar directives. Both mesoglcea and endoderm form very thin layers.
Nematocysts are present in the endoderm similar to those found in the endoderm
of the mesenteries and column in this region.

Mesenteries. — The arrangement of the mesenteries is brachycnemic. The im-
perfect mesenteries are well developed, sometimes extending about half way from
the body-wall to the oesophagus (PI. lxiv., fig. 9). The ectoderm of the oesophagus
is reflected a short way above the lower opening of the oesophagus, and forms the
mesenterial filaments in the usual way. The mesoglcea of the mesenteries is
comparatively well developed even in the oesophageal region, but it becomes much
thicker as it descends. Several canals run vertically through each mesentery.
Some of those appear to be connected in the ccenenchyme with the endoderm
(PI. lxiii., fig. 5). It is possible that others are connected with ectodermal
canals or lacunae, but we have not been able to trace any to the ectoderm. The
endoderm of the mesenteries is very similar to that of the body-wall. It
contains numerous small oval nematocysts. The muscles are fairly well
developed. The mesoglcea on each side of the mesentery, close to the body-
wall, is thrown into numerous and often branching plaits, which support the fibres
of the parieto-basilar muscle (PI. lxiv., fig. 9). On one side of each mesentery the
mesoglcea is thrown into very slight plaits all the way up. These plaits support
the longitudinal fibres. On the other side, the parieto-basilar fibres (cut obliquely
in transverse section) extend considerably beyond the mesogloeal plaitings. In
the imperfect mesenteries the mesogloeal plaitings extend the whole way on both
sides, and it is hardly possible to distinguish two distinct sets of fibres.

Gonads. — In only one of our specimens did we find gonads. These were all
female ; but they were few and not fully developed. We cannot say with
certainty whether this species is monoecious or dioecious, though our evidence
leads us to suppose it to be the latter.

Gemmaria, Duch. & Mich., 1860.

Solitary brachycnemic Zoanthese with mesogloeal sphincter muscle. The body-
wall is incrusted with grains of sand and spicules. The ectoderm is usually

Haddon and Shackleton — ActinicB : I. Zoanthece.

687

discontinuous, but may be continuous. Lacunas and cell-islets are found in the
mesogloea. Dioecious.

This genus was recovered by M°Murrich (1889), who identified a Zoantliid from
the Bermudas as Gemmaria rusei, Duch. & Mich. (p. 124), and in a previously
written, but subsequently published, Paper (1889a, p. 65), he describes G. isolata,
n. sp., from the Bahamas. We are able to extend the geographical distribution of
the genus, and at the same time give ourselves the pleasure of associating one of
our new species with the name of our esteemed colleague, Prof. J. Playfair
M°Murrich, of Haverford College, Pa., U. S. A., to whom we have so often
referred in these pages.

Besides the type species, G. rusei, from St. Thomas, Duchassaing and Michelotti
(1860) describe G. clavata, Duch. (St. Thomas and Guadeloupe), G. siviftii, D. & M.
(St. Thomas), and G. brevis, Duch. (Antilles).

In 1866 they state that "perhaps Gs swiftii may be better placed in the genus
Bergia." From the figure (1860, pi. viii., pp. 17 and 18) it appears to closely
resemble a Sarcodictyon, but in the later Memoir the authors state that it has 24
biserial tentacles. It is certain that this is not a synonym for Parasoanthus axinellce,
as Andres suggests (1884, p. 311). Anyhow it is clear that these authors had no
very definite conception of their own genus, for neither G. swiftii nor G. brevis
would appear to belong to the same genus as the type species, nor is it certain that
G. clavata does either.

It is difficult to understand why Andres (1884, p. 318) has regarded G. brevis
as a synonym of two or three species of Epizoanthus. Gray (1867, p. 238) has added
to the confusion by placing Z. sulcatus, Gosse, in this genus ; but it is probable
as McMurrich suggests, that Triga philippinensis, Gray (1867, p. 239), may belong
to the genus in question. Gray's description of the genus Triga: — "The coral
sub-cylindrical, solitary, attached, with a rather expanded base ; outer coat coria-
ceous, sandy, concentrically wrinkled"; and of the type species: — "Coral sub-
cylindrical, clavate, rather narrowed near the base, concentrically wrinkled ; end
convex, obscurely radiately striated ; hab. Philippines, attached to small pebbles
[Cuming). The coral varies from an inch to an inch and a-half in length " — agrees
very well, except for size, with our new species ; but without microscopical
examination it would be impossible to determine with certainty even the genus of
Gray's species.

The only known species of this genus are G. rusei, D. & M., G. isolata, M°M.,
G. macmurrichi, n. sp., and G. mutuJci, n. sp.

TOREES STRAITS SPECIES OF THE GENUS GEMMARIA.
G. macmurrichi, n. sp.
G. mutuki, n. sp.

688 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

Gemmaria macmurrichi, n. sp.

(PI. lxl, fig. 11 ; PI. LXIII., fig. 7.)

Form. — Erect, rigid, wider above than below; upper portion of contracted
specimen with minute radiating corrugations.
Colour. — Sandy.

Dimensions. — Height, 13 mm.; diameter, 3*5 mm. above, 2 mm. below.

Locality. — Channel between Mer and Dauar, Murray Islands. 20 fathoms.
Mar. 16, 1889. One specimen only.

Body-wall (PI. lxiil, fig. 7). — The ectoderm is discontinuous, being broken
up by thick, irregular strands of mesoglcea, which unite to form a distinct peri-
pheral layer lying beneath the cuticle. The ectodermal cells are for the most
part disintegrated in our specimen, their contents adhering to the surrounding
mesogloea and leaving an empty space in the centre. The incrustations consist
chiefly of coarse grains of calcareous sand, but a few silicious sponge spicules are
also present, and are left after decalcification. Beneath the incrustations lies an
encircling sinus, which is, however, so much interrupted by the mesoglcea as to
appear in horizontal section as a circular series of lacuna?, each lacuna lying imme-
diately below the union of a mesentery with the body- wall, two or three lacunae
being occasionally united by a fine canal. As the base of the polyps is approached
the lacunas gradually become smaller and finally disappear. It thus appears that
the body-wall is pierced by a number of canals, which run vertically upwards from
near the base to the disc of the polyps ; these canals being occasionally connected
with each other by much finer crossing canals. Similar fine canals are occasionally
to be found running from the vertical canals outwards towards the ectoderm. Cell
islets are scattered abundantly through the mesoglcea, as also are single cells
elongated into delicate fibrils connected both with endoderm and mesoglcea, such as
we have described in other species of Zoantheae. Large lacunae, densely filled with
deeply staining granules, are numerous at the base of the polyp. These are clearly
connected with the mesenterial canals which arise in this region. They seem to
be of ectodermal origin. The endoderm which lines the column is not very well
preserved, but it appears to form a regular layer of medium thickness. The
muscular layer is well developed in the upper part of the column. Lower down it
is weaker.

Sphincter muscle. — The sphincter muscle is single, mesoglceal, and is well developed.

Disc and tentacles. — Unlike the two species of Gemmaria described by M°Murrich,
the ectoderm of the disc and tentacles contains no zooxanthellae, nor have we ob-
served them in the endoderm either. The ectodermal muscular layer is fairly

Haddon and Shackleton — Actinia : I. Zoanthew.

689

well developed in our specimen, whilst in his it is very weak (1889, p. 124). Cell
enclosures (similar to those described and figured by McMurrich) are found in the
disc of G. macmurrichi. Foreign bodies are occasionally found embedded in the
mesoglcea of this region.

(Esophagus. — The tissues of the oesophagus are badly preserved in our specimen.
There is a slight thickening of the mesogloea at the groove, but we are unable to
give further particulars.

Mesenteries. — The mesenteries are arranged as in other Brachycneminse. The
mesoglcea is well developed in both imperfect and perfect mesenteries. The
muscular layer appears to be feebly developed, the mesogloeal plaitings not being
well marked. A vertical canal runs through each mesentery, from the base of the
polyps to the disc ; in many cases it appears to divide, giving rise to two or more
canals in the oesophageal region. The reflected ectoderm and the filaments are so
badly preserved that it is impossible to make out the particulars of their arrange-
ment. The endoderm of the mesenteries is very similar to that which lines the
body-wall.

Gonads. — There were no gonads in our specimen.

This species can easily be distinguished anatomically from the two species
investigated by McMurrich, but externally they appear to be very similar.

Gemmaria mutuki, n. sp.

(PI. LXI., fig. 10.)

Form. — Erect, wider above than below ; upper portion of retracted specimens
with a large number (24—30) of fine radial ridges, which are continued some way
down the column; lower portion of column wrinkled in spirit specimens. Basal
gemmation occurs.

Colour.—- Grayish-white in spirit.

Dimensions. — Height, 10—12 mm. ; average diameter, 4.5 mm.
Locality. — Mabuiag, 6th October, 1888 ; 5 specimens.

We have named this species after a local hero, Mutuk by name, whose adven-
tures are recorded in the Journal of the Folk-lore Society, " Folk-lore," I., 1890,
p. 56.

Body-wall (fig. 1, p. 690). — The ectoderm is continuous, and is covered by a thin
cuticle to which numerous diatoms adhere. Occasional zooxanthellse are to be found
in the ectoderm. The mesoglcea is rather thin relatively to the diameter of the polyp.
Numerous incrustations are embedded in the mesoglcea. They are chiefly spicular ;
ascidian as well as sponge spicules being frequently found. Grains of sand are

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PABT XIII.

690 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

also present. Cell enclosures consisting for the most part of lacunae are very

numerous in the mesoglcea. There is no

lac.-v: "

eni. —

Fig. 1. — Gemmaria mutulci. Transverse
section of body-wall.

The

regular series of canals or of lacunas lying
at the union of each mesentery with the
body-wall, such as we have described for
G. macmurrichi. In some parts of the wall,
the lacunae lie so close together beneath the
incrustations, as to suggest an interrupted
encircling sinus ; but for the most part they
are irregularly scattered through the meso-
glcea. Zooxanthellae are found in many of
these lacunae. The endoderm forms a uniform

layer of moderate thickness in which zooxanthellae are very numerous,
muscular layer is well developed.

Sphincter muscle. — The usual single mesoglceal sphincter muscle is present.

Disc and tentacles. — As in the body-wall, zooxanthellae are present in both
ectoderm and endoderm in this species, though they are much less abundant in
the former than in the latter layer. The ectodermal muscular layer is rather
weak. In both these features it will be seen that G. mutulci differs from G. mac-
murrichi, and resembles McMurrich's two West Indian species. The mesoglcea of
the disc in this sj)ecies also contains cell enclosures.

(Esophagus. — The groove is well marked, and of the truncated form described
and figured by McMurrich for G. isolata (1889 a, p. 66, PI. iv., fig. 20).

Mesenteries. — The mesenteries have the usual brachycneniic arrangement. The
mesoglcea is fairly well developed ; the musculature is rather weak. Each
mesentery contains a single basal canal, which does not divide in the cesoj)hageal
region as in G. macmurrichi, but runs up vertically from the base of the polyp
almost to the disc. The tissues in the lower part of the ccelenteron in our
specimen are unfortunately not sufficiently well preserved for us to give details
regarding the mesenterial filaments.

Gonads. — Numerous ripe sperm cells are present in the ccelenteron of the
specimen cut by us.

Externally this species may be distinguished from G. macmurrichi by its
shorter, more stumpy form. Anatomically it differs from G. macmurrichi in
the presence of numerous zooxanthellae, in the continuous ectoderm, and in
various other points, which will be seen by comparing our description of the two
species. Outwardly, G. mutuki may also be readily distinguished from the two
West Indian species, but in several anatomical points, referred to above, it seems
to agree more nearly with them than with G. macmurrichi.

Haddon and Shackleton — Actinice : I. Zoanthece.

691

PALYTHOA, Lamx., 1816.

Corticifera, Lesueur, 1817. Polythoa, Andres, 1884.

Mammillifera (pars), Blainville, 1830. Polythoa (Corticithoa), Andres, 1884.

Brachycnemic Zoanthese with a single mesogloeal sphincter muscle. The body-
wall is incrusted. The ectoderm is continuous (?); the rnesoglcea contains numerous
lacunae, and occasionally canals. Dioecious. Polyps immersed in a thick ccenen-
chyme, which forms a massive expansion.

The genus Palythoa was founded by Lamouroux (1816, p. 359) for the
reception of two species which had previously been described and figured by Ellis
and Solander as Alcyonium mammillosum and A. ocellatum (1786, pp. 179, 180, PI. i.,
figs. 4—6). Palythoa is thus defined by Lamouroux : — " Polypier en plaque
e'tendue, couverte de mamelons nombreux, cylindriques, de plus d'un centimetre
de hauteur, re'unis entre eux ; les cavite's ou cellules isole'es, presque cloisonnes
longitudinalement et ne contenant qu'un seul polype."

Palythoa mammillosa is evidently regarded by Lamouroux as the type species
of the genus. He reproduces Solander's figure of this species, but not that of
P. ocellata, of which he merely gives a description. Unfortunately a Latinized
version of the French name " Palythoe* Etoille'e," given by Lamouroux to P.
mammillosa, has been added at the bottom of his plate — a circumstance which has
given rise to some confusion.

In 1817 Lesueur, being evidently unacquainted with Lamouroux's work,
erected the genus Corticifera for two West Indian species which he named C. gla-
reola and C. fiava. These species are evidently very nearly allied to P. mammillosum
and P. ocellata : indeed Lesueur queries whether C. flava is not synonymous with
Alcyonium ocellatum, Ellis and Sol. ; and his definition of the genus Corticifera
agrees very nearly with that of Lamouroux for Palythoa.

Subsequent naturalists have, with very few exceptions, recognized the priority
of Lamouroux's genus, and have applied the name Palythoa to all those Zoanthese
which are incrusted with sand, and are immersed to a greater or less extent in the
ccenenchyme, forming corticiferous expansions. In this sense Verrill used the
term in 1869, and Hertwig in 1882 adopted the same classification.

Unfortunately the genus Palythoa has also been occasionally extended to
include Zoanthese which are incrusted with sand, but which are united only at the
bases, forms which are included in the genus Epizoanthus, as defined by Verrill
(1869, p. 437). Amongst the species to which the name Palythoa was thus
mistakenly applied was a form with ribbon-like ccenenchyme and exsert polyps,
described by Schmidt as P. axinellce (1862, p. 61).

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692 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

In 1885 Erdmann, investigating the anatomy of a number of forms which, to
judge from their outward characters, should all be relegated to the genus Epizoan-
thus, discovered, that, in reality, they belonged to two distinct natural genera,
distinguished by the circumstance that some of them possessed a single mesoglceal
sphincter muscle, whilst in others the sphincter was endodermal. Amongst
the latter was Schmidt's species P. axinellce. Those species which possessed a
mesoglceal sphincter muscle Erdmann retained in the genus Epizoanthus. Those
which had an endodermal sphincter, he placed in the genus Palythoa, ignoring
P. mammillosa, and adopting P. axinellce as typical of the genus, thereby excluding
the type species, as well as numerous closely allied forms which had hitherto borne
the name Palythoa.

It was now necessary to find another name for these forms, and Erdmann
consequently revived Lesueur's genus Corticifera, a genus which, as we have
pointed out above, was synonymous with Palythoa, but had to give place to that
genus on the grounds of priority. To the former definition of the genus
Corticifera Erdmann added certain anatomical characters — namely, the " micro-
typal " (brachycnemic) arrangement of the mesenteries and the presence of a single
mesoglcea sphincter muscle. These anatomical characters have been shown to be
present in all the species recently investigated which are included in Lamouroux's
Palythoa and in Lesueur's Corticifera, including the type species C. glareola
(re-examined by McMurrich, 1889, p. 122). It therefore appears that they all
belong to one and the same morphological genus, which, as we have shown, must,
according to the laws of priority, be known as Palythoa. To sum up, the
argument may be briefly stated as follows : — 'Palythoa, Lamx. = Corticifera, Les. =
Palythoa, Verrill, &c. Schmidt and others extended Palythoa to include P.
axinellce and similar species, thus, unconsciously, making the genus Palythoa both
macro- and brachycnemic.

Erdmann restricted the genus Palythoa to the non-typical macrocnemic exten-
sion, and revived Corticifera for the typical brachycnemic species. We restore
Lamouroux's genus, discard Corticifera, and erect a new genus, Parazoanthus, for
P, axinellce and allied species.

As regards P. mammillosa, the type species of Palythoa, we may say
that we are strongly inclined to regard C. lutea of Hertwig (1888, p. 44,
PI. I., fig. 6) as being synonymous with P. mammillosa. M°Murrich agrees with
us in regarding Hertwig's identification of his West Indian form with Quoy and
Gaimard's Mammillifera lutea, from the Fiji Islands, as doubtful in the extreme ;
but he is inclined to believe Hertwig's species to be identical with C. glareola, which
he describes (1889, p. 122). However this may be, we feel quite justified in
assuming that the anatomical characters of P. mammillosa are similar to those of
all the other species possessed of similar outward characters, which have been
anatomically examined.

Haddon and Shackleton — Actiniae : I. Zoanthece.

693

TORRES STRAITS SPECIES OF THE GENUS PALYTHOA.

P. hotvesii, n. sp.
P. kochii, n. sp.
P. coesia (?), Dana.

Palythoa howesii, n. sp.
(PI. lxi., fig. 13; PI. lxiii., fig. 8.)

Form. — Polyps scarcely projecting above the surface of the coenenchyme when
contracted, and then, in most cases, only the one side is prominent ; in other words,
the side is almost invariably entirely sunk. Coenenchyme, thick, incrusting. The
polyps are arranged in indefinite, roughly parallel rows. Owing to the partial
immersion of the polyps the prominent portions of contiguous polyps have a
tendency to form zigzag lines. The whole surface is very rigid and rough,
owing to the incrustation of sandy particles.

Colour. — Sandy.

Dimensions. — Average diameter of polyps, 7 mm.
Locality. — Fringing reef, Thursday Island. One colony.

Named after Prof. G. B. Howes, of the Royal College of Science, London.
[I would like to take this opportunity of acknowledging the assistance which my
friend Professor Howes has rendered me from first to last in the storing and
distribution of my Torres Straits collections. — A. C. H.]

Body-wall (PI. lxiii., fig. 8). — As in other species of Palythoa, the body-wall
and coenenchyme are indistinguishable. The ectoderm which covers the surface
of the colony is much torn, fragments of it alone adhering to the mesoglcea ; these
pieces are further broken by irregular projections of the mesoglcea, which somewhat
resemble the mesoglceal strands found in various other species of Zoanthese, but
they do not appear to unite in this case to form a peripheral layer of mesoglcea.
In most cases no cuticle is to be seen, but in one or two places we have found a
thin cuticle, and it seems probable that in a normal condition such a cuticle covers
the surface of the ectoderm. The mesoglcea is very thick, and the incrustations
are chiefly found in the outer portion. The incrustations consist of coarse
grains of sand, and are very numerous. Lacunae, some of which are clearly
connected with the ectoderm, are scattered through the mesoglcea. In some cases

694 Reports on the Zoological Collections made in Torres Straits, 1888—1889.

the canals in the mesenteries, which are extremely well marked, are distinctly
connected with the spaces in the body-wall. Large yellowish nematocysts are
present in the outer ectoderm, in many of the lacunae of the mesogloea, and in the
mesenteric canals, being especially numerous in the latter. A very few zooxan-
thellse are also present. Besides the lacunae, numerous isolated cells are enclosed
in the mesogloea, many of them being drawn out into the fine protoplasmic threads
found in other species of Zoantheae. The endoderm is granular, of uniform
thickness, and contains occasional zooxanthellse. The usual diffuse muscular
layer is present.

Sphincter muscle. — The single mesoglceal sphincter muscle is well developed.

Disc and tentacles. — The ectoderm is thick, and in the tentacles the ectodermal
muscular layer is well developed, the mesoglceal folds being complicated and
branching. The mesogloea also forms a thick layer and often contains cell
enclosures. The endoderm is very thin.

(Esophagus. — The ectoderm of the oesophagus was not well preserved in our
specimens, so that it was not possible to determine its nature or arrangement in a
normal condition. There is a well marked groove, and the mesogloea, which
elsewhere is thin, becomes much thickened in this region.

Mesenteries. — The mesenteries present the usual microcnemic arrangement. The
imperfect mesenteries are usually well developed. The ectoderm of the oesophagus
appears to be reflected in the usual manner, but owing to its bad preservation it is
not possible to determine the exact nature of its arrangement. The mesogloea is well
developed, and in each mesentery it contains one or more sinuses or canals which
extend throughout the entire height of the mesentery. These sinuses contain
numbers of large nematocysts, similar to those found in the ectoderm of the body-
wall. The muscles of the mesenteries are not strongly developed. They form
almost simple layers.

Gonads. — The sexes are distinct; we found female, but no male gonads, in
several of the polyps which we examined. They were all taken from the same
colony.

Palythoa kochii, n. sp.
(PI. lxi., fig. 12; PI. lxih., fig. 9.)

Form. — Polyps projecting slightly above the surface of the ccenenchyme ;
ccenenchyme incrusting, of moderate thickness. Polyps so crowded as to usually
have a polygonal contour. The whole surface is incrusted with calcareous particles,
etc. Twenty capitular ridges and furrows. Tentacles, 40. Mouth large.

Colour. — Colour of colony, finely speckled buff and cream, each polyp demar-
cated by a pale border ; tentacles similar, but translucent. Disc thin, translucent,

Haddon and Shackleton — Actinice : I. Zoanthew.

695

the dark interval cavity shining through ; very finely dotted with brown and
opaque white. (Esophagus gray, furrowed. Capitular ridges whiter than the rest
of the polyp.

Dimensions. — Diameter of polyps about 5 mm.

Locality. — Fringing reefs, Thursday Island, and Mabuiag.

This species is named in honour of our distinguished German colleague, who
was the first to discover the precise arrangement of the mesenteries in the
Zoanthese.

Body-wall (PI. lxiii., fig. 9). — As in the last species the body-wall and
ccenenchyme may be regarded as one. The ectoderm, where present, is continuous,
and is covered by a thin cuticle. Incrustations, consisting of spicules and grains
of sand (the latter being for the most part less coarse than those found in P. hoivesii),
form a dense border at the union of the ectoderm with the mesoglcea. They are
scattered more sparingly through the deeper parts of the mesoglcea. Lacunas,
canals, and cell islets are found throughout the mesoglcea. Nematocysts are present
in both the ectoderm and the lacunas. Zooxanthellae are also found in the ectoderm
and lacunae, as well as in the endoderm. The endodermal muscle is well developed.
The endoderm forms a uniformly thin layer.

Sphincter muscle. — The mesoglceal sphincter is long and well developed.

Disc and tentacles. — The structure of the disc and tentacles is very similar to
that found in P. howesii.

(Esophagus — The ectoderm of the oesophagus is not well preserved, but it appears
to be thrown into well marked folds. There is a very slight groove, and no
appreciable thickening of the mesoglcea in this region.

Mesenteries. — The mesenteries are arranged as in other Brachycneminse. The
imperfect mesenteries are well developed. The reflected ectoderm is not well
preserved, but is evidently arranged in the ordinary manner. Sinuses, similar to
those found in P. hoivesii, are found in the mesenteries of this species also. The
muscular layers are very simple, there being apparently no mesogloeal plaitings.

Gonads. — We found male gonads in several of our specimens, but no female
organs were present.

Palythoa coesia(?), Dana.
(PI. lxi.j fig. 14.)

Palythoa ccesia :

Dana, 1846, Zoophytes, U. S. Exploring Expedition, p. 40. pi. xxx., figs. 3, 3a. Milne
Edwards, 1857, Hist. Nat. Coralliaires, i., p. 305. Andres, 1884, Le Attinie, p. 332.

Form. — Polyps slightly projecting above the surface of the ccenenchyme when
contracted. Ccenenchyme incrusting in small, ovoid, concavo-convex masses of

696 Reports on the Zoological Collections made in Torres Straits, 1888—1889.

moderate thickness. Polyps large, not crowded, of rounded contour. The whole
surface is incrusted with calcareous particles. About twenty capitular ridges.
Colour. — Grayish-white in spirit specimens.

Dimensions. — Diameter of polyps about 9 mm. The colonies in the specimens
before us average about 50 cm. by 40 cm.
Locality. — Reefs, Torres Straits.

We have doubtfully referred this species to P. coesia, which was collected by
the United States Exploring Expedition at Fiji. The size and disposition of the
polyps are fairly similar in the two forms ; but the ccenenchyme of ours is less
convex. From the specimen figured (PI. lxi.,
fig. 14), it would seem that the colony divides
after it has attained a certain size.

Body-wall. — In its anatomy this species is in
most respects very similar to that of P. kochii.
The ectoderm is covered by a thin cuticle, and
is continuous. It contains nematocysts and
zooxanthellae. Incrustations are even more
numerous than in P. kochii, and they penetrate
the mesoglcea, which separates the polyps to a
greater extent than in that species. They con-
sist of sponge and ascidian spicules, foramini-
fera, &c, as well of great numbers of grains
of sand. Lacunae of variable size are very
numerous in the mesoglcea. In some cases a
great number of these lacunae placed close to-
gether form a sort of spongy or vesicular sheath
round an individual polyp. Nematocysts are
commonly to be met with in the lacunae. The
endoderm is not very well preserved, but it
appears to form ridges between the mesenteries,
rather than a thin uniform layer as in P. kochii.
The endodermal muscular layer appears to be
well developed:

Sphincter muscle. — The single mesoglceal sphincter is a strong one.

Disc and tentacles. — The disc and tentacles are very similar in structure to
those in the last two species, the ectoderm being remarkably thick.

(Esophagus. — Nematocysts are very numerous in the ectoderm of the oesophagus.
There is a well marked groove.

Mesenteries. — The arrangement of the mesenteries is brachycnemic. The

Fig. 2. — Palythoa cmsia (?). Transverse
section of body-wall.

Haddon and Shackleton — Actiniae: I. Zoanthece.

697

mesenteries in other respects seem to be very similar to those of P. howesii and P.
kochii. Well marked sinuses extend through each mesentery from the base to
the disc.

Gonads. — We have found no generative organs in this species.

The more irregular disposition of the polyps distinguishes P. kochii from P.
howesii, in which they are arranged more or less in rows. The zigzag appearance
due to the partial immersion of the polyps is very characteristic of P. howesii. It
would require considerable care to distinguish between P. kochii and certain other
species of the genus. P. coesia, as identified by ourselves, is easily distinguishable
from the preceding species on account of the large and non-crowded polyps and
the apparently smaller size of the colonies ; but we would like to add another
warning as to the extreme difficulty in identifying the species of this genus.

SPHENOPUS, Steenstrup, 1856.

Free, solitary, brachycnemic Zoanthese, with a single, very long, mesoglceal
sphincter muscle. The body -wall is incrusted. Cell islets present in the mesoglcea.

Sphenopus arenaceus, Hertwig.

Sphenopus arenaceus :

Hertwig, 1882, Voy. H. M. S. " Challenger," Zoology. Report on the Actiniaria, p. 120, pi. n.,
fig. 10 ; pi. xiv., fig. 8. Also, 1886, ibid., Supplement, p. 52.

Hertwig says, in his first report of this species : — " Habitat — Cape York ? (the
title of the label enclosed with the preparation was nearly entirely destroyed
by the rough surface of the animal, and could not be exactly made out), one
specimen." In the Supplement he says: — "Habitat — Station 187, Torres Strait,
Australia, September 9, 1874 ; 6 fathoms. Two specimens. ... In the ' Chal-
lenger' material I have found four further examples of the genus Sphenopus ; two
of these I have determined as Sphenopus arenaceus, on account of their rusty red
tint, and other two Sphenopus marsupialis, in consequence of the earthy-gray colour
and the absence of a stalk." The last being a character of his other new species,
S. pedunculatus (I. c. p. 49), from off Panay, Philippine Islands.

This is the only Zoanthean previously recorded from Torres Straits, and it does
not occur in our collection. Thanks to the kindness of Professor F. Jeffrey Bell,
of the British Museum, we have been able to examine some specimens of S. mar-
supialis which were given to him by Edgar Thurston, Esq., of the Central
Museum, Madras, who collected them at Madras.

Hertwig gives no characters by which this species can be distinguished from

THANS. HOY. .DUB. SOC, N.S. VOL. IV., PART XIII. 5 H

698 Reports on the Zoological Collections made in Torres Straits, 1888-1889.

S. marsupialis, and we agree with him when he says it is u desirable that with an
opportunity of more abundant and fresh material, a renewed study should be
undertaken to decide whether the received specific characters are variable, and
whether all three species should not be united in the single Sphenopus marsupialis
(I. c. p. 52).

Sub-family. Macrocnemiisle.
PARAZOANTHUS, Hadd. & Shackl., 1891.

Macrocnemic Zoanthese with a diffuse endodermal sphincter muscle. The body-
wall is incrusted. The ectoderm is continuous ; encircling sinus as well as ecto-
dermal canals ; lacunae and cell-islets in the mesoglcea. Dioecious. Polyps connected
by thin ccenenchyme.

This genus is established by us in our second part of the Revision of the British
Actiniae (1891, p. 653), to which the reader is referred for fuller details.

TOEEES STEAITS SPECIES OF THE GENUS PARAZOANTHUS.

P. dichroicus, n. sp.
P. douylasi, n. sp.

Parazoanthus dichroicus, n. sp.

(PI. lxl, fig. 15 ; PI. lxii., fig. 5.)

Form. — Body short, encrusted with sand and spicules. Capitulum with about
eighteen distinct ridges. Ccenenchyme encrusting a specimen of Plumularia
ramsayi.

Colour. — Body and ccenenchyme, gray ; capitulum, pale-yellow.
Dimensions. — 2—2*5 mm. in height ; 1*25— 1 '5 mm. in diameter.
Locality — Channel between Mer and Dauar, about 20 fathoms, Jan. 6, 1889.
One colony.

This species rendered the alcohol in which it was preserved strongly dichroic —
the colours being yellow and violet ; we have emphasised this fact in its name,
which is also appropriate on account of the gray and yellow colour of the polyps.

Body-tvall. — The body-wall is thickly incrusted with foreign bodies, particles of
sand, diatoms, ascidian and sponge spicules, &c. (PI. lxii., fig. 5). These are em-
bedded in the mesoglcea, the ectoderm having for the most part disappeared from

Haddon and Shackleton — Actiniae : I. Zoanthece.

699

the surface of our specimens. Where present the ectoderm appears to be con-
tinuous. It is not penetrated by strands of mesoglcea, nor is there a peripheral
layer of mesoglcea. The cuticle is very delicate, and difficult to discern. Beneath
the incrustations, and separated from the endoderm by a narrow band of mesoglcea,
is an encircling sinus filled with dark brown granular pigment. It is crossed at
intervals by strands of mesoglcea. A few branching canals connected with the sinus
run outwards through the mesoglcea among the incrustations. Small, round or
oval groups of cells, the cell-islets of Erdmann, are scattered throughout the
mesoglcea; a very few pigment granules can be seen in some of them. We have
not observed any connexion between the sinus or the canals connected with
it and these islets. The endoderm is richly pigmented. We have seen no
zooxanthellae.

The capitulum, which in contracted specimens is thrown into deep folds, is
also incrusted ; but there is a much larger proportion of spicules and relatively
fewer sand particles than in the column. The encircling sinus is not continued
into the capitulum.

Sphincter muscle. — The endodermal sphincter is supported on slightly branched
plaitings of mesoglcea. Near the upper extremity (in contracted specimens) it
appears to become embedded in the mesoglcea, a few simple cavities being visible
in our sections.

Tentacles. — The ectoderm of the tentacles is thick. The nuclei are scattered
diffusely through the outer part, leaving a clear band next the muscular layer.
Small nematocysts of the usual description are present. The mesoglcea is thin and
almost homogeneous, a very few cell-islets being present. The endoderm contains
a few zooxanthellse, and occasional pigment granules.

Disc. — The ectoderm of the disc is very similar to that of the tentacles, but it
contains some pigment. Numerous cell-islets occur in the mesoglcea.

(Esophagus. — The ectoderm of the oesophagus stains more deeply than that of
the disc or tentacles. It forms a simple layer, not being thrown into folds. The
mesoglcea is fairly thick, especially in the region of the groove, which is well
marked.

Mesenteries. — The mesenteries are arranged as in other Macrocneminae. The
imperfect mesenteries are very slightly developed, projecting but little beyond the
endoderm. The mesoglcea of the mesenteries is thick, and contains cell-islets, but
no canals or sinuses. The longitudinal muscles are well developed and supported
on mesoglceal folds. The endoderm resembles that which lines the body-wall.

Gonads. — In one of the specimens cut by us male gonads were found.

Parasites. — Small, oval, deeply pigmented bodies occur in many parts of the
body in this species. They are evidently parasites, but we are unable to say
anything further about them.

700 Reports on the Zoological Collections made in Torres Straits, 1888—1889.

Parazoanthus douglasi, n. sp.

(PL lxi., figs. 16-22; PI. lxii., fig. 6.)

Form. — Body when growing on hydroids often somewhat long and relatively
narrow, but when growing on a flat surface, usually short and thick ; capitular
ridges not well marked ; texture gritty ; ccenenchyme incrusting.

Colour. — Sand colour.

Dimensions. — Height variable; largest specimens 8—9 mm. ; diameter, 2-2*5 mm.
The shorter specimens growing on flat surfaces are from 3—5 mm. in height, and
2 mm. in diameter.

Locality. — Albany Pass, Cape York. 10 fathoms. August 29, 1888. Numerous
specimens.

[I have named this species in honour of the Hon. John Douglas, K.C.M.G.,
Government Resident at Thursday Island, Torres Straits, who assisted me as far
as was in his power during my stay in Torres Straits. — A. C. H.]

Body-wall. — As in P. dichroicus, but little ectoderm remains on the body-wall of
our specimens of P. douglasi, and that which does remain is continuous and covered
by a very delicate cuticle. The incrustations, which penetrate the greater part of
the thickness of the mesoglcea, consist chiefly of sponge spicules (some of them being
triradiate) with a few grains of sand, foraminifera, &c, amongst them. There
is an encircling sinus which contains a few dark granules similar to those which
are so abundant in P. dichroicus, but it is for the most part almost empty. It is
crossed at intervals by the strands of mesoglcea, and is connected with a system of
branching canals, which run outwards through the incrustation. Cell-islets, though
present, are not at all so numerous as in P. dichroicus. The endoderm forms a thin
layer of uniform thickness. The muscular layer is feebly developed.

Capitulum. — The incrustations in this region are almost entirely confined to
sponge spicules. The ridges, although not externally conspicuous, can be well
seen in our transverse sections.

Sphincter muscle. — The spincter muscle is entirely endodermal. The mesoglceal
plaitings are regular and simple.

Disc and tentacles — The structure of disc and tentacles is very similar to that
of P. dichroicus, but there appear to be no enclosures of any kind in the mesoglcea.

(Esophagus. — The ectoderm of the oesophagus is thrown into slight folds. There
is a distinct groove, the mesoglcea being much thickened in this region.

Mesenteries. — The arrangement of the mesenteries is brachyenemic. The imper-
fect mesenteries are even more feebly developed than in P. dichroicus, being in
many cases hardly discernible. The mesoglcea forms a fairly thick layer,

Haddon and Shackleton — Aciinice : I. Zoanthece.

701

without enclosures of any kind. It is thrown into very slight plaitings to support
the longitudinal muscles, which are not well developed. The parieto-basal
muscles are also feebly developed. The endoderm of the mesenteries forms a thin
layer similar to that which lines the body-wall.

Gonads. — No gonads were found in our specimens.

Parasites. — We found that many of our specimens of this species were infested
by a copepod which deposits its egg in the ccelenteron or coelenteric canals of the
polyp. The capsules are paired, and contain a large number of ova. We have
found them in the nauplius stage, as well as in other stages of development. We
have two specimens of the copepod, but are unable to say whether these are adult
or not. The capsules form distinct swellings of the body-wall of the actinian.
This fact leads us to suppose that the copepod remains within the coelenteric
cavities while the capsule is developing, and when the latter is ripe it breaks
away from it (PI. lxl, figs. 19—22).

Small oval parasites, similar to those found in P. dichroicus, are also found
in P. macmurrichi.

The larger size and uniform colouration of P. douglasi enable it to be easily
distinguished from P. dichroicus.

TRANS. BOY. DUB. SOC, N.S. VOL. IY., PART XIII.

5 1

EXPLANATION OF PLATE LXI.

TRANS. ROY. DVB. SOC. N.S. VOL. IV.. PART XIII.

PLATE LXI.

Fig.

1. Zoanthus coppingeri, n. sp. (p. 676). Natural size ; spirit specimens.

2. Zoanthus coppingeri. Drawn from living specimen by A. C. H.
3-4. Zoanthus jukesii, n. sp. (p. 678). Sketched from life by A. C. H.

5. Zoanthus jukesii. Natural size ; spirit specimens.

6. Zoanthus macgillivrayi, n. sp. (p. 680). Twice natural size ; drawn from spirit specimens by

A. C. H.

7. Isaurus asymmetricus, n. sp. (p. 684). Natural size ; drawn from life by A. C. H. ; one speci-

men is drawn, showing the smooth side.

8. Isaurus asymmetricus. Entirely smooth specimen.

9. Isaurus asymmetricus. Small variety from Murray Island ; natural size ; drawn from life by

A. C. H.

10. Gemmaria mutuki, n. sp. (p. 689). Natural size ; spirit specimens.

11. Gemmaria macmurrichi, n. sp. (p. 688). Twice natural size; drawn from spirit specimen by

A. C. H.

12. Palythoa kochii, n. sp. (p. 694). Portion of colony; natural size ; spirit specimen.

13. Palythoa howcsii, n. sp. (p. 693). Portion of colony; natural size ; spirit specimen.

14. Palythoa ccesia? (Dana) (p. 695). Portion of a bilobed colony; natural size ; spirit specimen.

15. Parazoanthus dichroieus, n. sp. (p. 698). Natural size ; spirit specimen.

16-17. Parazoanthus douglasi, n. sp. (p. 700). Natural size; spirit specimens.

18. Parazoanthus douglasi. Natural size; portion of a dried colony incrusting stones; dried
specimen.

19-22. Copepod Galls on P. douglasi —

19. Portion of ccenenchyme-wall of gall.

20. Side view of one of the egg-capsules in situ.

21. Showing a pair of egg-capsules in situ.

22. Two empty galls in base of polyps.

[All the above are in the British Museum, with the exception of fig. 11, of which the single
specimen obtained was utilised for anatomical examination.]

Trans. RDub.S.N.S.Vol.IV.

Pla te LXI.

M.f. Parker del.et lith

West^evmuLn irrrp

EXPLANATION OF PLATE LXII.

PLATE LXII.

LETTERING ADOTTED IN THE FIGURES.

e.i., . .

cell-islets.

mes. lac,

. mesenterial lacuna.

. cuticle.

mes. sin.,

. mesenterial sinus.

ect., . .

. ectoderm.

m.f., . . .

. mesenterial filament.

ect. can.,

ectodermal canal.

nematocyst.

e»c. sin..

. encircling sinus.

. ovum.

end. , . .

endoderm.

. parasite.

. incrustation.

x., . . .

. axial support of incrusting form

. mesogloea.

a.. . . .

. zooxanthella.

[The axial support in fig. 5 is a Hydroid.]

Fig.

2

1. Zoanthus coppingeri, n. sp. (p. 676). Transverse section through the base of the body- wall, — .*

2

2. Zoanthus jukesii, n. sp. (p. 678). Transverse section through the base of the body-wall, — .

XL

2

3. Zoanthus macgillivrayi, n. sp. (p. 680). Transverse section through the base of the body-wall, — .

A.

4

4. Isaurus asymmetricus, n. sp. (p. 684). Transverse section through the base of the body-wall, # .

2

5. Parazoanthus dichroicus, n. sp. (p. 698). Transverse section through the base of the body-wall, ^.

2

6. Parazoanthus douglasi, n. sp. (p. 700). Transverse section through the base of the body-wall, — .

* These letters of magnification refer in all cases to Zeiss' system.

A M S. del. ad nat.
MP .Parser ehr.litb

West, lMcv/t nan hit

EXPLANATION OF PLATE LXIII.

PLATE LXIIL

LETTERING ADOPTED IN THE FIGURES.

hr. cn. Dies., .

. brachycnemic mesentery (the sulco-

. mesoglosa.

sulcar lateral mesentery).

mes. can., .

mesenterial canal.

. coelenteron.

m. sph. in., .

. mesoglceal sphincter muscle.

. cuticle.

. nematocyst.

decal.,

lacuna due to the decalcification of

. oesophagus.

an incrustation.

s. d., . .

. sulcar directive mesenteries.

ect., . . .

. ectoderm.

s. gr., . .

. sulcar groove.

. ectodermal bay.

. sulcular directive mesenteries.

. endoderm.

vert, can.,

, vertical canal.

end. can.,

. endodermal canal.

z., . . .

. zooxanthella.

. incrustation.

Fie.

1. Zoanthus jukesii, n. sp. (p. 678). Transverse section through the oesophageal region of the
column, — ^

a* 10

2. Zoanthus macgillivrayi, n. sp. (p. 680). Transverse section through the lower portion of the

3

column,

a* 8

2

3. Isaurus tuberculatum (Gray), (p. 617 of British Zoanthe^;). Section through an ectodermal bay, — .

2

4. Isaurus asymmetricus, n. sp. (p. 684). Vertical section through a sphincter muscle, —

«* 10

5. Isaurus asymmetricus. Transverse section through a portion of the centre of the base of the

column, .

2

6. Isaurus asymmetricus. Transverse section through the periphery of the body-wall, — .

2

7. Gemmaria macmurrichi, n. sp. (p. 688). Transverse section through the body -wall (decalcified),

2

8. Palythoa howesii, n. sp. (p. 693). Transverse section through the body-wall (decalcified),

2

9. Palythoa hochii, n. sp. (p. 694). Transverse section through the body -wall, -g.

Traiis.R.Dub.S..N.S.,Vol.IV.

Plate LX11I.

A M.S del ad iiat.

"Wee t .Newman, in

EXPLANATION OF PLATE LXIV.

PLATE L X I V.

LETTERING ADOPTED IN THE FIGURES.

■ cuticle.

mes. can.,

mesenterial canal.

d. m. sph., .

. double mesoglceal sphincter muscle.

mes. sin.,

. mesenterial sinus.

ectoderm.

m. /., . .

. mesenterial filament.

ect. can., .

. ectodermal canal.

n. c, . . .

nerve-cell.

endoderm.

nematocyst.

end. b., .

. endodermal bay.

oesophagus.

end. can!.,

. endodermal canaliculus.

ov., . . .

ovum.

end. m., .

. endodermal circular muscle of ten-

p. b. m.,

. parieto-basilar muscle.

tacle.

r. ect., . .

. reflected ectoderm.

/• b., . . .

. food-ball (?).

1. in., . .

. longitudinal muscle.

t.,.. . .

. tentacle.

m., . . .

. mesoglcea.

z

. zooxanthella.

Fig.

2

1. Zoanthus coppingeri, ri. sp. (p. 676). Transverse section through the body-wall, j-.

2

'I. Zoanthus coppingeri. Transverse section through the wall of a tentacle,-^.

3. Zoanthus coppingeri. Verticle section through the half of a polyp ; slightly diagrammatic ; the
ectoderm, ectodermal canals, mesoglcea, mesenteric canals, gonads, and sphincter muscle are

3

a* 6

coloured red ; the endoderm and the endodermal canals are coloured blue,

2

4. Zoanthus coppingeri. Transverse section through a perfect mesentery, — .

5. Zoanthus macgillivrayi, n. sp. (p. 680). Vertical section through a portion of a polyp, -5—

a* 8

6. Zoanthus macgillivrayi. Transverse section through part of a perfect mesentery, with reflected

2

ectoderm, — .

C

7. Zoanthus macgillivrayi. Transverse section through a perfect mesentery, showing the upper portion

of the mesenterial filament, — .

0

8. Zoanthus macgillivrayi. Transverse section through a perfect mesentery, showing the lower portion

of the mesenterial filament, .

9. Isaurus asymmetricus, n. sp. (p. 684). Transverse section through two perfect and one imperfect

2

mesenteries in the oesophageal region ; also showing an endodermal bay, — .

Tr.-u. s.R. Dub. S.,X. S.,Vol.IV.

Plnte LXJV

[ 703 ]

XIV.

ON THE FOSSIL FISH-REMAINS OF THE COAL MEASURES OF THE
BRITISH ISLANDS. PART I. — PLEURACANTHIDiE. By JAMES W.
DAVIS, F.O.S., F.L.S., F.S.A., &c. Plates LXV. to LXXIII.

[Read January 20, 1892.]

[communicated by the honokaky secretaries.]

I. -INTRODUCTION.

It is proposed in this work to describe, and where desirable to figure, the fossil
fishes whose remains have been discovered in the several coal fields of Great
Britain. For the purposes of this work the Coal Measures will include all the
strata between the uppermost bed of Millstone Grit at their base, and the Permian
Rocks which immediately overlie them. The subject is a large one, and for
convenience of publication, as well as in the preparation and arrangement of the
material, it appears advisable to divide it into a series of monographs, commencing
with the Elasmobranchii, and of this sub-class the Pleuracanthidae will first receive
attention. Except incidentally, the stratigraphical distribution of the fish-remains
will be considered later, when all the available material shall have been examined
and recorded.

I cannot neglect the present opportunity to express my indebtedness to those
gentlemen having the charge of public or private museums, for their uniform
courtesy and kindness in permitting me to visit their collections, and still more for
the readiness with which such parts of the collections as were necessary for com-
parison or identification have been placed at my disposal. Amongst such instances
I may mention the Natural History Department of the British Museum, Cromwell-
road, London; the Museum of the Natural History Society of Northumberland,
Durham, and Newcastle-on-Tyne ; the Manchester Museum at the Owens College ;
the Woodwardian Museum at Cambridge; the Museums of the Philosophical
Societies at Leeds, Halifax, and York ; the Hunterian Museum at Glasgow, and
the Museums of Science and Art at Edinburgh and Dublin.

TRANS. ROY. DUB. SOC, N.S. VOL. IV., PART XIV. 5 L

704 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Amongst the owners of private collections I am greatly indebted to my friends
and co-workers, James Thomson, Esq., of Glasgow ; Dr. J. R. S. Hunter, of Carluke,
and R. Dunlop, Esq., of Airdrie, in Scotland; George Wild, Esq., of Bardsley,
and James Nield, Esq., of Oldham, in Lancashire ; Professor Louis C. Miall, of
the Yorkshire College, and T. W. Embleton, Esq., of Methley, in Yorkshire ;
to William Dinning, Esq., of Newcastle, an able palaeontologist, to whose manipu-
lative skill science is indebted for some of the most beautiful examples figured
in the present monograph, I owe many thanks. No worker in this branch of
palseichthyology can afford to do without the assistance of John Ward, Esq., of
Longton, in Staffordshire; his great collection, unique in many respects, and the
result of many years of patient investigation, is invaluable ; and to this collection,
and the practical knowledge possessed by Mr. Ward, willingly placed at my disposal,
I am under deep obligations. And lastly, to A. Smith Woodward, Esq., whose
fellowship is very dear to me, I am indebted for many helpful courtesies and
kindnesses, which may perhaps be more easily understood than expressed.

II. — CLASSIFICATION AND DESCRIPTION.

Class. — PISCES.

Sub-Class I. — ELASMOBRANCHIL

Order I. — Ichthyotomi (E. D. Cope and A. Smith Woodward).

Syn. — Xenacanthidse, H. B. Geinitz, C. F. Liitken, Anton Fritsch; Pteryga-

canthidse, Ch. Brongniart.

Endoskeletal cartilage permeated throughout with granular calcifications ;
notochord rarely or never constricted ; calcifications of the sheath arrested at
the most primitive rhachitomous stage, except in the caudal region. Neural and
haemal arches and spines long and slender ; with or without intercalary cartilages.
Pectoral fins with long segmented axis (archipterygimn).

Family.— PLEURACANTHIDiE. A. Smith Woodwaed, Ch. Brongniakt.

Syn. — Xenacanthidae, Anton Fritsch.

Body slender, but slightly depressed ; mouth terminal ; tail diphycercal ; dorsal
fin elongate, low, continuous along the back from a point shortly behind the head ;
slender interneural cartilages more numerous than the neural spines. Pectoral fin
with biserial arrangement of cartilaginous rays.

J. — Pleuracanthidce.

705

Genus Pleuracantkus, Agassiz. " Rech. sur les Poissons Fossiles," 1837,

vol. iii., p. 66.

T)l TilofJllS

J—/ -L Ul UU. XJLioj • •

Aoakstz E 1843 " Poiss Eoss " vnl iii n 204

Ort h 3 pn nthns

AfiASSiz L 1843 fom e?7 vol iii r»n 177 330

111 Y1W "fi cr« 7 f)

X • Al, 1 ^ *

P ti fi p Pi v\ t n n

./XCXXCH^CXXX IXX LlOj • •

Pfyrtoh E 1818 u "RpnVlit K Prpnss Akad

flpv Wi Q^pri qpVi f pii " n 9,4-

Liv>X H XDOCXXDVvXXClX I/CTII , IJ* /i/A.

Jordan 1849 " Npiips Jnhrb " r» 843

■ C wXl.J-/ixlN j 1 U If . Xi Vj LI V_/kj u till J. !.'m LJ • UT(J«

rlornrmfl pati f nil ^

Nfwrfrry J S 1856 "Proo Apad Nat Spi"

Philadelphia," p. 100.

T)i tf on n ^

X-/ J. L l» >_L Llo, • • •

Owfn P 1867 "Trans Odont Sop " vol v

Aganodus,

Owen, R., 1867, fern. czY., p. 359.

Ochlodus,

. Owen, R., 1867, fom. p. 346.

Pternodus,

. Owen, R., 1867, torn, cit, p. 363.

Trinacodus,

. St. John and Worthen, 1875. " Palaeont. Illinois,"

vol. vi., p. 289.

Lophacanthus,

. Stock, T., 1880. "Ann. Mag. Nat. Hist." series 5,

vol. v., p. 217.

Didymodus,

. Cope, E. D., 1883. " Proc. Acad. Nat. Sci. Phila-

delphia," p. 108.

Body comparatively elongated ; skin destitute of shagreen ; head large and
depressed ; cranium consisting of segments, more or less ossified, separated by
sutures; mouth terminal, widely extended; jaws bearing numerous teeth
(Diplodus), arranged as in the Selachii ; notochord persistent ; neural and haemal
arches ossified, the ossification presenting a mosaic appearance due to granular
calcifications; seven gill arches (Fritsch) the seventh arch without gills; gill
rakers present (Stemmatodus) ; head surmounted by a spine, straight or slightly
curved ; opening of internal cavity of spine terminal ; along some part of the sur-
face extends two rows of denticles ; these may be widely separated and lateral
(Pleuracanthus) ; they may be in close proximity along the posterior surface
(Orthacanthus) or the two rows may occupy any intermediate position between
the two. Attached to the spine is a small cephalic fin ; dorsal fin commencing
immediately behind the head extends to the base of the caudal ; the fine rays sup-
ported by interspinous and surapophysial bones more numerous than the neural
spines ; tail diphycercal with a pointed extremity ; pectoral fins supported by a
long articulated axis (archipterygium) with a bi-serial arrangement of semi-osseous

706 Davis — On the Fossil Fish- Remains of the Coal Measures of the British Islands.

lateral cartilages; ventral fins with an articulated axis supported by a pair of
triangular pelvic cartilages and lateral cartilages on external surface ; in the males
the fins are provided with claspers ; two anal fins placed one behind the other,
attached to the hsemapophyses by a series of intermediate ossicles.

The genus Pleuracanthus was instituted by Agassiz* and embraced a fish spine
from the coal shales of Dudley ; its surface was rounded and at the same time
depressed and armed on each side by a range of denticles arched towards the base.
The spine was considered to belong to an undescribed genus of the family of the
Rays. One species was described, P. Icevissimus, Ag.f A second species was
referred to six years later, but not described, viz. P. planus, Ag., in the same volume,
p. 177. This was from the Coal Measures in the neighbourhood of Leeds. The
type specimen is in the Egerton collection at the Natural History Museum,
London, and is now determined as the spine of a young example of P. Icevissimus.
Prof. Agassiz refers on the same pagej to another spine, Orthacanthus cylindricus, Ag.,
from the Coal Measures at Leeds ; and again when considering the defences of the
Rays, 0. cylindricus is described as a straight spine of cylindrical form armed with
two rows of sharp denticles on the posterior surface. The spine is stated to be
from the Coal Measures in the neighbourhood of Manchester. The near relation-
ship of Orthacanthus with the genus Pleuracanthus is recognized.

In 1841, Mr. E. W. Binney first noticed certain teeth from the Lancashire
coal field to which he appended the name Diplodus gibbosus.§ The specimen was
figured but without description; the latter was given by Agassiz,|| and specimens
were described from the Coal Measures of Staffordshire and of Carluke in
Scotland.

Dr. Goldfuss 51 described a specimen ascribed to the genus Orthacanthus from
the lower Permian Sandstones of Ruppersdorf in Bohemia exhibiting the upper
surface of the head and a large portion of the body. The mouth was large and
terminal with numerous rows of small three-pronged teeth. The spine, still
in position, was embedded in a cartilaginous mass immediately behind the head.
It was round, with a median ridge on the dorsal aspect ; and on each side the
ridge, separated by a narrow groove, was a row of denticles. The spine was
on front of the first dorsal fin, considered subsequently by C. Brongniart,**
as a cephalic fin. The second long dorsal fin was without spine. The pectoral
arch is described as being built up, on either side of an internal bone, composed

* Rech. sur les poissons fossiles, vol. iii., p. 166. 1837. f Op. tit., pi. xlv., figs. 4 and 5.

% Op. tit., p. 177 and p. 330, pi. xlv., figs. 7-9. 1843.
§ Trans. Manchester Geol. Soc, vol. L, p. 169, pi. v., figs. 17-18.
|| Op. tit., p. 204, pi. xxrr. b, figs. 1-5.
Beitrage zur vorweltlicnen Fauna des Steinkohlengebirges, p. 23, pi. v., figs. 9-11, 1847, Bonn.
** Bull. Soc. de l'lndustrie Minerale, ser. 3, vol. ii., 1888.

/. — Pleuracan thidce.

707

of a single piece, which towards its hinder part is bent on its outer edge in the
form of a knee. This edge supports a number of fin-rays, the anterior ones fine
and short, those behind longer and thicker. From the knee-shaped angle
springs a strong distinctly jointed ray (axis of archipterygium). To this are
attached, on its outer margin, seventeen thick strong rays ; and on its inner
margin a number of smaller and closer rays. In the Ruppersdorf specimen
it is not clear by what means the knee-shaped bone was attached at its proximal
extremity. The ventral fins are similarly connected to those of the pectoral. A
broad, short geniculate bone was suspended from the vertebral column, and to
this was attached an articulated primary ray as in the pectoral fin ; but they
differ from the pectorals in having lateral rays only on the outer margin.

M. Beyrich described and discussed, a year later, the relationship of a
fish * similar in all essential respects to the Orthacanthus described by Goldfuss,
except that in this specimen the spine was flattened before and behind, and
had on each side rows of sharp, short, hook-shaped, backward-pointing teeth.
To this fish the new generic name Xenacanthus was given, and the opinion
expressed that Orthacanthus Dcchenii ' of Goldfuss must be given up in its favour ;
and further that though the spine is evidently the same genus as the Pleuracanthus
of Agassiz, which has priority, the latter is only known as the name of a spine, and
consequently must give way to Xenacanthus, which represents a more or less
perfect fish.

Sir Philip de Malpas Grey Egerton, at the meeting of the British Association
at Glasgow, in the year 1855, drew attention to the generic identity of the spines
called Pleuracanthus and Xenacanthus, and the teeth named Diplodus ; and in
1857.t he published a paper in the " Annals and Magazine of Natural History," in
which the claim of Pleuracanthus to priority over the other names is enforced, and
consequently it should stand as the name of the genus.

It was suggested by Prof. H. B. Geinitz that the ventral plates might have
been a sucker, and the fish allied to the genus Cyclopterus.%

In 1867, Prof. D. Rudolph Kner published a memoir, " Ueber Orthacanthus
Decheni. Goldf. oder Xenacanthus Decheni Beyr."§ Specimens located in the
museums of Dresden, Berlin, Breslau, Vienna, and others are described in detail.
Kner argues that the two genera named, along with Diplodus teeth, are identical,
as was stated by Goldfuss twenty years previously. The fish is described as
having a large head, somewhat flat, with a large rounded terminal mouth. The
pectoral fins were broadly expanded and the body tapered towards the tail. The

* Bericht der Konigl. Preussischen Akademie der Wissenschaften, p. 24, 1848.
f Ann. Mag. Nat. Hist., ser. 2, vol. xx., p. 423.
% Der Dyas, p. 23, pi. xxin., fig. 1, 1861.

§ Sitzungsberiehte Kaiser. Akad. "Wiss. "Wien, vol. lv., pt. i., p. 540, pis. i.-x. 1867.

708 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

body may have been covered with shagreen, but in the specimens available for
observation the skin was without scales or other protection. The spine was ap-
parently one-fourth to one-fifth of the entire length of the fish ; it was implanted
in the occipital cartilage without articulation. The vertebral column was noto-
chordal, more or less encircled by the bony extremities of the apophyses ; ribs,
short and rudimentary, were present, with the articulating extremity broad, and
the opposite one pointed. Immediately behind the spine there originated a dorsal
fin, which extended along the back to the caudal extremity. In addition to the fin
rays and the spinous processes attached to the vertebral column, there were two
series of interspinous bones. This arrangement extended to a short distance
beyond the ventral fin. The smaller interspinous bones, surapophyses of Fritsch,
next to the neurapophyses, then disappear, and the longer interspinous bones con-
tinue nearly to the caudal extremity of the body. A fin also extended along the
ventral surface of the body, and joining the dorsal one formed a single-lobed tail.

Dr. Kner describes four or five gill arches, furnished with a few long teeth.
The skull was of so soft and cartilaginous a nature that the orbits are obliterated,
and no evidence is afforded of any segmentation of the covering of the skull. The
constituents of the cranium and the jaws were recognized as consisting of cartilage
filled with closely approximating ossicular centres. This enamel-like arrangement
was compared by Beyrich to a species of mosaic. The upper jaws are stated to
consist of maxillary bones, with pre-maxillaries attached, both provided with
teeth.

The organs attached to the ventral fins, considered by Dr. Geinitz to have
been suckers, were described by Dr. Kner as hooking organs similar to the claspers
of sharks found at the present time, and this opinion he enforced by the observa-
tion that some of the fishes possessed these appendages and others did not ; those
possessing them being the male fishes, and those devoid of them being females.

Messrs. Hancock and Atthey found the teeth of Diplodus, associated with large
patches of thick granular substance resembling shagreen, in the Coal Measures of
Newsham and Cramlington, in Northumberland. This association led them to
write :* — " There can be little doubt that these shagreen-like patches are the
remains of the skin of some large fish, and that the Diplodi are dermal tubercles
in connexion with it, and analogous to the spinous tubercles of the Rays. At the
same time it must be admitted that it is possible enough that the larger specimens
may have clothed the lips or jaws with a spinous pavement resembling in arrange-
ment the oral armature of the Rays or Cestracions." The authors describe the
great variation in size and form of the so-called dermal tubercles, and recognize
that the D. minutus, Ag., belongs to the same species as D. gilbosus. It is also

* Nat. Hist. Trans. Northumberland and Durham, vol. iii., p. 111. 1879.

/. — Plenracan thidce.

709

pointed out that the genera Dittodus, Aganodus, Pternodus, and Ochlodus, described
by Prof. Owen, are all referable to Diplodus, and had been established on varying
examples, more or less fragmentary, of the teeth of that genus.*

A Paper was published by the writer in 1880,§ on the genus Pleur acanthus,
Agass., in which several new forms of spines are described, principally derived
from the cannel coal at Tingley, near Leeds, but also from the Staffordshire coal
field and Lower Coal Measures of the West Riding of Yorkshire. These spines
exhibited a number of intermediate forms between Pleur -acanthus Icevissimus, Ag.,
and Orthacanthus cylindricus, Ag. The latter possesses two rows of denticles,
which are situated comparatively close together on the median posterior surface,
whilst the former has also two rows of denticles on the sides of the spine and as
widely separated as it is possible that they could be. The examples described in
the Paper " prove that the difference in the relative position of the two rows of
denticles must either be of small generic importance or that many new genera will
have to be formed for their accommodation. Almost every intermediate form
between the two is now known ; the denticles extend at every angle between the
sides and back of the spine." After careful consideration the opinion is enunciated
that the several spines were borne by fishes having characters of a single generic
type, and that they should consequently be included, under different specific deter-
minations, in the genus Pleur acanthus. The Diplodus teeth have hitherto been
found indeterminately associated with the spines of Pleur acanthus, Xenacanthus,
and Orthacanthus, and afford additional evidence of their generic identity.

Professor E. D. CopeJ has recorded the occurrence of more or less complete
crania from the Permian beds of Texas. The specimens also include jaws and
numerous teeth. The teeth are indistinguishable from Diplodus gibbosus, Ag., and
Diplodus compressus, Newb. The latter is provisionally referred to a distinct
genus, and styled Didymodus. Twelve more or less well-preserved crania were
examined, one of which exhibited the jaws with teeth and a part of the cranium.
The skull formed a continuous piece with distinct segmentation ; it was elongated
posteriorly and abbreviated anteriorly, the orbit occupying a position on the
anterior third of the cranium with well-defined pre-orbital and post-orbital
processes. The top of the muzzle is described as being " excavated by a
fontanelle which does not extend posterior to a line connecting the pre-orbital
processes." The occipital elements form a wedge-shaped body divided medially
by a suture with the apex forward. A second triangular bone is the parietal ; its
apex is concealed beneath the free extremity of the bone preceding it. On each
side, between the occipital and parietal elements are bones which Professor Cope

* Trans. Odont. Soc, vol. v., 1867.

f Quart. Journ. Geol. Soc, vol. xxxvi., p. 321, pi. xii.

\ Proc. American Phil. Soc, vol. xxi., p. 572, with plate. 1884.

710 Davis— On the Fossil Fish-Remains of the Coal Measures of the British Islands.

considers may be the intercalare or pterotic. The element in front of the parietal
is the cartilaginous representative of the frontal, which terminates posteriorly in
two free processes. There are also "distinct paired membrane bones which
appear to represent the frontals in Ceratodus" '; each is a flat, subcrescentic
supra- orbital plate, which has a concave superciliary border. It is separated by a
considerable interval from its fellow on the opposite side. A fossa on its anterior
extremity is supposed to represent the anterior nostril.

The occipital bone includes ex-occipital and basi-occipital elements combined.
There is a prominent cup-shaped occipital condyle. The occipital extends only a
short distance on the inferior surface, and is attached directly and without
imbrication, to a continuous axial element which it is suggested is a combination of
the sphenoid and pre-sphenoid bones. The upper jaw, consisting of palatine and
pterygoid elements without division, was apparently articulated with the post-
orbital process of the cranium. The posterior border of the palato-pterygoid forms
a prominent rim descending to the mandible and forming a regular ginglymus,
the mandible bearing the cotylus. The mandible is robust ; inferior edge thin
and incurving anteriorly. The superior border is regular, only rising a little in
the coronoid region corresponding with a concavity in the pterygoid region. A
portion of a hyo-mandibular bone is exposed.

These remarkable specimens constitute the first recorded discovery of the
skulls of Pleur acanthus, showing that they were divided by sutures into segments,
and this Prof. Cope considered was a sufficient reason for the institution of a new
order of the Elasmobranchii, which he names the Ichthyotomi.

A very interesting series of specimens, between twenty and thirty in number,
have been found by M. Fayol in the Coal Measures of Commentry, Allier, in
France. These were forwarded to M. Charles Brongniart, of the Museum of
Natural History, Paris, and have been described and figured as Pleur acanthus
Gaudryi, Brong.* They vary in length between 0*5 and 1*0 m., and the head
occupies about one-fifth the length of the fish. It is not possible, in any of the
specimens, to distinguish the pieces composing the head. The jaws are rounded
in front and furnished with small teeth along their borders. On one specimen
four grooves were distinguishable, probably representing the branchial arches.
The spine is straight, pointed, and on the upper part on each side is a row of
denticles, recurved towards the base of the spine, which most nearly approaches
P. Frosardi, Gaudry, and P. pulchellus, Davis. " Derriere l'aiquillon cdphalique
se dressent de petits rayons r^unis a lui par une membrane, formant ainsi une
nageoire que nous appellerons cephalique." This fin is stated to be similar to that

* " Etudes sur le terrain houiller de Commentry," Bull. Soc. de l'Industrie Minerale, ser. 3, tome n.
4ieme Livr. 1888, pis. i.-vi., woodcuts 1-15.

/. — Pleuracan thidce.

711

of Cestracion, except that it is in a more advanced position. The dorsal fin
extends the whole length of the back to the base of the caudal, equal to
three-fifths the entire length of the fish. The dorsal fin, as previously shown
by Kner* in specimens from Klein-Neundorf, is supported by a complicated
series of rays. The bony neurapophyses are broad at the base, forked above ;
to each branch of the fork is attached a short ray, the surapophysial, to which
is attached the interspinous ray supporting the fin-ray. The caudal fin encircles
the posterior extremity of the body. Its upper lobe is supported by a series
of rays similar to those of the dorsal fin, except that the surapophyses are absent ;
and nearer the extremity the interspinous bones also disappear. The hsema-
pophyses are more robust and longer than the neurapophyses, but have no rays
attached : the first five or six hfemal arches are composed of two parts, united
at their base and encircling the notochord. Further back they diminish in
length and lose this character. The scapular and clavicular elements of the
shoulder girdle are cemented into one piece, and their junction forms the point
of attachment of the pectoral fin. The central support of the fin consists of a
jointed pterygium, the elements composing it gradually diminishing in size, the
last being long and filiform. From the external margin of this axis spring the
fin-rays, varying in length, and articulated. On the internal margin there is a
smaller number of rays, not articulated. M. Charles Brongniart considers the
pectoral fin of Pleuracanthus to exhibit characteristics intermediate between the
biserial articulated pterygium of Ceratodus and the pectoral fin of Acanthias
vulgaris. The pelvic arch has a general resemblance to the pectoral, but it is
smaller. Each fin is attached to a moiety of the arch, similar in form and
comparable in parts to the scapula and clavicle of the pectoral arch. The median
axis is composed of cylindrical cartilaginous elements placed end to end, but
diminishing little, if any, in size, and the fin-rays are attached only to the
external margin. The axis, instead of being straight, as in the pectoral fin,
is curved and forms the arc of a circle. To the extremity of each axis is attached
a piece which can only be regarded as an appendix to the genital organs,
similar to the claspers in the sharks, rays, and chimera. These are found
only on the male fishes. In the female the pelvic fins are feebler, and the
median axis terminates within the membrane of the fin.

There are two anal fins which have remarkable peculiarities. They are
lobate, rounded, contracted at the base, enlarged in the middle, and again
contracted towards the extremity. Both fins are similarly constructed. The
haemapophyses to which they are attached are shorter and more inclined than
those of the caudal region; they are truncated instead of pointed, and three

* Sitzungsberichte Kaiser. Akad. Wiss. "Wien, vol. lv., pt. i., p. 540, pis. i.-x. 1867.

TB.A-NS. BOY. BUB. SOC, N.S. TOL. IV., PABT XIV.

112 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

in number. The first and second have attached to them interspinous bones
and fin-rays. The third is larger, broad at the two extremities, slightly curved,
and towards the middle, on the concave side, is a sort of apophyse, to which
is attached an interspinous ray and a fin-ray ; its extremity supports a shorter
and broader ossicle. The latter affords attachment to three elements — first, a
long and pointed ray, extending backwards, and two ossicles, of which the
posterior one supports two short ossicles and fin-rays, and the anterior one
one ossicle and one fin-ray. " Ces nageoires anales pr^sentent done une structure
tres complexe et rappellent par leur disposition de veYitables membres."*

Mr. A. Smith Woodward has pointed outf that the teeth of Didymodus are
generically indistinguishable from those of Diplodus, and he has included the two
in the genus Pleur acanthus. This author is also convinced that the presence of
membrane bones % in the skulls of the Texas specimens is more than problematical,
and founded on a misconception. Eeporting on a recent visit to Professor Cope's
collection of fish and other fossil remains at Philadelphia, Mr. Woodward says§ the
skulls of the Ichthyotomous Elasmobrancli "Didymodus" certainly exhibit with
distinctness the extraordinary Assuring of the chondro-cranium, though in the
strict sense of the term it is scarcely accurate to name the segmented parts
" bones."

During the years 1889 and 1890 Dr. Anton Fritsch of Prague published two
parts of his important work on the gas coal of Bohemia, || which are almost entirely
occupied with the genus Pleur acanthus, as now defined. Dr. Fritsch prefers to
regard Pleur acanthus, Xenacanthus, and Orthacanthus as distinct and independent
genera, and bases his diagnosis upon the teeth, spines, and denticular appendages
of the gill arches, taken in conjunction with the construction of the archipterygium
and fin-rays of the pectoral fins. Four species of Orthacanthus are described, viz.
0. Bohemicus, Fr. ; 0. Kounoviensis, Fr. ; O.pinguis, Fr. ; O.plicatus, Fr. ; and a fifth,
0. Senkenbergianus, Fr., is from Lebach. The remains are of a more or less frag-
mentary character. The remains of Pleuracanthus and Xenacanthus are much
more perfect, and the study of them has enabled Dr. Fritsch to add considerably
to our knowledge of the Pleuracanths. Only one species of Xenacanthus is recog-
nized, the type X. Decheni, Goldf., whilst there are four species of Pleuracanthus
from the Bohemian formations described, they are, P. ovalis, Fr. ; P. CElbergensis,
Fr. ; P. carinatus, Fr. ; and P. parallelus, Fr. The denticles on the spines of both
genera are lateral, but the cavity is said to be smaller in Pleuracanthus than in
Xenacanthus, and there is in the former an external median groove on the posterior

* Op. cit., p. 23. f Cat. Foss. Fishes, Brit. Mus., pt. i., p. 3. 1889.

X Op. cit., Introd., p. xxiii. § Geol. Mag. Dec, nr., vol. vii. Sep., 1890.

|| Fauna der Gaskohle mid der Kalksteine der Permformation Bohmens, Band n., Heft 4, pp. 98-112,
pis. lxxxi.-xc., 1889 ; and Band in., Heft 1, pp. 1-48, pis. xci.-cn., 1890.

_T. — Pleuracanthidce.

713

surface. The pectoral fins do not differ greatly in Orthacanthis and Pleura-
canthus, but in Xenacanthus the fin is shorter proportionately to the others, and
there are dermal fin-rays, which the others do not possess. The skull is described
as consisting of a continuous cartilage, without segmentation or membrane ossifica-
tion, and there are seven gill-arches ; the shoulder girdle is more or less similar to
a gill-arch. The spine is attached to the posterior portion of the cranium and is
not attached to a fin. The cartilaginous skeleton exhibits a granular calcification.
The vertebral column is notochordal, the neural and haemal arches are largely
ossified, and in two genera there are intercalary cartilages. The pelvic fins are
provided with claspers in mature male fishes. The form and structure of the anal
fins is fully elucidated. The work is illustrated with numerous figures, in addition
to the plates, mostly taken from galvanoplastic models of the original specimens.

Dr. Fritsch sums up the result of his work on this family in the following
terms : — Die Haut enthielt keine Schuppen. Das Knorpelskelet istin alien seinen
Theilen mit Kalkprismen durchsetzt. Der Schadel ist eine einheitliche Kapsel
ohne alle Deck-Knochen. Der Nackenstachel sitzt auf einer Papille der Schadel-
kapsel und ist mit keiner Flosse in Verbindung. Die Wirbelsaule ist notochord, mit
verkalktem centralen Faserstrang, Wirbelkorper kommen nieht zur Entwickelung.
Das System der oberen Wirbelbogen ist stark entwickelt und bei zwei Gattungen
kommen Intercalaria vor. Es sind sieben Kiemenbogen vorhanden. Der Schul-
tergurtel ist mit einem Kiemenbogen vergleichbar. Die paarigen Flossen ent-
wickelten sich aus einer Reihe ursprunglich neben einander liegenden Strahlen.
Die Glieder des sogenannten Hauptstrahles entstanden theils durch Verdickung der
Glieder eines Strahles, theils durch Verschmelzung mehrerer Nebenstrahlen. Ein
Becken ist nicht vorhanden. Das Basalstiick der Bauchflosse entstand durch
Verschmelzung von Flossenstrahlen. Die Pterygopodien der alten Mannchen
sind ahnlich gebaut wie die der jetzigen Haie und auch bei alten Weibchen kamen
ahnliche Hilfsorgane ftir die Begattung zur Ausbildung. Die ovalen Eier sind
festschalig."

Hitherto the descriptions of the fossil remains of this genus from the Coal
Measures of Great Britain have been confined to examples of the spines variously
considered as those of Pleuracanthus or Orthacaiithns and teeth named Diplodus.
The discovery of a number of isolated spines in the Coal Measures of the
West Riding of Yorkshire,* exhibiting a very varied series of forms, has led to
the conclusion that the spines named by Agassiz, as above, can only be regarded
as modifications of the same genus. Diplodus teeth have been found associated
almost indiscriminately with both forms of spine, and render the possibility
of any distinction into genera still more remote. In other instances the teeth

* Quart. Journ. Geol. Soc, vol. xxxvi., p. 322, pi. xn., and woodcuts. 1880.

5 M 2

714 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

found associated in a single jaw are so divergent in form that specific distinction
of isolated examples becomes quite problematical. The spines certainly offer
more persistent and better defined characters than the teeth. A comparison
of the figures of the teeth in the fine series of specimens it is now proposed
to describe from the Newcastle coal field will confirm this view. Had all the
teeth been obtained as individual specimens they might reasonably have served
for description as different species. Notwithstanding these difficulties, the
occurrence of numbers of apparently well-defined and persistent forms, some-
times found only in one locality and stratum, and in others characteristic of
several localities, renders necessary their description as separate species.

In addition to the isolated specimens of spines and teeth there have been
found masses of shagreen, with an occasional well-preserved archipterygial fin,
or single specimens of spinous or interspinous processes, in the Coal Measures of
the West Riding of Yorkshire ; but the most valuable and interesting series of
specimens has been discovered in the Lowmain coal seam at Newsham, in
Northumberland, and is contained in the Atthey collection, recently purchased
by Lady Armstrong, and placed in the museum at Newcastle-on-Tyne. From
the same locality, a second collection, containing most remarkable examples, has
been acquired by Mr. William Dinning, of Newcastle. Examples from both
collections are described in the following pages. The fishes varied very much
in size, from an example measuring nearly half a metre across the head and
with a possible length of three or four metres, to a head represented by the
exquisitely preserved cranium in the possession of Mr. Dinning, which has a
diameter of only one-tenth of a metre. The latter specimen is the only one
found on this side the Atlantic exhibiting a cranium in which the several
elements are separated by sutures. The beautiful series of examples found in
Bohemia and described by Dr. Fritsch ; or those equally well, or perhaps better,
preserved found at Commentry, in France, and described by M. Chas. Brongniart,
exhibit the cranium only as a mass of cartilage without segmentation. The
fossil remains described by Professor Cope as " Didymodus," obtained from the
Permian beds of Texas, possessed crania which showed the component parts
forming a continuum displaying distinct segments. The example in the collection
of Mr. Dinning exhibits the surface configuration of the cranium with great
clearness.

The upper and lower jaws are exhibited, in relative position to each other,
in a very fine specimen at the museum at Newcastle. The specimen was
excavated and developed by the late Mr. Atthey. On one side of the slab the
two lower jaws are preserved, with large cranial plates lying near, and on the
opposite side the upper jaws are exposed, with numerous teeth, as well as the
reverse sides of the plates exhibited with the lower jaws. This specimen probably

I. — Pleuracanthidce.

715

indicates the largest example of the genus known; and compared with the complete
examples obtained from the strata of Bohemia or Comm entry, the Newsham fish
must have been between three and four metres in length.

The lower jaws are 0*45 m. in length, the posterior part of the jaw is 0*11 m.
in height, and diminishes to about half that amount anteriorly. As in the lower
jaw exhibited in Plate lxv., its posterior portion appears to have had centres of
ossification bounded by more or less angular borders (fig. la), and giving it the
appearance of being composed of a series of plates. The left jaw (fig. lb) is in a
normal position, the right has been to some extent flattened out, which gives a more
largely expanded surface than it probably possessed in a natural state. The outer
borders of the two lower jaws correspond in position with those of the upper
jaws exhibited on the opposite side of the slab, and the latter have impressed
their form on the former, giving them the appearance of having a thicker border
than they really possess, but for which they would no doubt have got credit
had the specimen been less perfect. Numerous teeth are scattered between and
about the jaws. The right ramus of the lower jaw is somewhat broken, as shown
in the figure, but the depression of the surface (fig. la a) may indicate the position
where articulation has been. A thickening of the bone appears to show that the
articulating surface was in its immediate vicinity.

To the right of the left mandible (fig. 16) there are two or more large cranial
plates. The one marked (fig. Id) is 0*20 m. in length and 0'13 m. in breadth; it
has a convex outer margin corresponding in curvature with the inner one which
is concave. Both ends of the plate were probably attached to other bones ; the
outer convex margin is thicker and stronger than the other parts. The form of
this plate is similar to the one marked (a) in Mr. Dinning's specimen (PL lxvii., fig. 2)
which occupied a position on the margin of the cranium in a line with the occipital
plates. Another large osseous plate (fig. le) occupies an area in advance of the one
described. The mass is 0*24 in length, and may consist either of a single plate or
more probably of two ; it is more rectangular than the one mentioned before, and
probably extended in front of it towards the anterior part of the skull.

The opposite side of the specimen is no less interesting. The palato-pterygoid
constituting the upper jaws are exposed as well as the cranial plates marked
d and e of the figures of the other side. The outer margin of the jaws is nearly
circular (PI. lxvi.), and from right to left the diameter is 0*43 m. A line drawn from
the symphysis of the rami to the posterior extremities of the jaws is 0'44m. in
length. The outer margin of the jaws is thicker than the remaining portion, and
as previously observed has impressed its form on the opposing lower jaws. The
posterior extremity of the right jaw, which is perfectly exposed, is narrow, the
inner margin being concave and the diameter 0*07 m. at a distance of 0*07 m.
from the end. From that point it rapidly expands and joins up to the opposing

716 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

jaw with a long- straight suture extending along the median line of the palate. Its
broadest part is 0*14 m. The inner margin is comparatively thick, but much less
so than the outer margin ; the intermediate area is apparently thin, but of the
same chondroid or granular structure as the other portions, the usual osseous
centres being abundantly intermixed with the cartilaginous base.

The wide expansion of the palato-pterygoid bone over the palate is remarkable.
The researches of Dr. Anton Fritsch have shown that the bone in the palatine region
extends high up the side of the head, diminishing anteriorly and extending to
the snout in a more or less attenuated form. This magnificent specimen exhibits
a lateral expansion from the anterior portion of the jaws, so as to form a pair of
osseous plates extending to the median line of the palate and there joining
together. In the German specimens of Pleuracanthus (Xenacanthus) Dr. Kner
considered that the upper jaw was divided into maxillary and premaxillary, but
in this specimen there is no evidence of this unless the elements at the nasal
extremity can be so construed. The Texas example, described by Professor Cope,
showed the upper jaw to consist of a single bone on each side the palato-pterygoid.
This view is also supported by the specimens described by Dr. Fritsch.

The large expansion of the palato-pterygoid over the palatal area of the mouth
in this specimen does not extend to the anterior extremity of the jaws, but a
triangular area starting at a point where the two rami are most anteriorly in
juxtaposition, 0 08 m. from the nasal extremity, is occupied by a number of smaller
semi-osseous pieces mixed with numerous teeth ; these apparently completed the
anterior portion of the wide rounded snout, and probably represent the pre-
maxillary. There is at the anterior termination of the palato-pterygoid a
thickened concave margin which has apparently served for attachment to the
pieces composing the snout. The several parts, however, are not so well pre-
served as to enable a reproduction of the natural arrangement to be made
(PI. lxv., fig. Ice), This peculiarity is indicated in the specimen described
by Dr. Jordan in the Neues Jahrbuch in 1849, and afterwards figured by Dr.
R. Kner,* in which the under surfaces of the upper jaws are exhibited, separated
by a distinct interval at the anterior extremity.

The teeth are numerous and vary considerably in form. The average length is
0*015 from the base to the extremity of the denticles. The form may have borne
some relationship to the position the teeth occupied in the mouth, but in this
specimen, as in nearly all the others, the teeth are scattered in indiscriminate
confusion over the slab, and only a very rough estimate can be made as to their
original position. There are a few teeth, however, which appear to be in their
proper places attached to the anterior portions of the jaws. They are smaller

* Sitzungsberichte Kaiser. Akad. Wiss. Wien, vol. lv., pt. I., p. 568, pi. vi., fig. 1. 1867.

7". — Pleuracanthidce.

717

than the majority, which probably occupied a posterior position. The lateral
denticles are comparatively strong, and they are considerably bent inwards ; the
median denticle is shorter and thicker than that of the teeth further back
(PI. lxvi., fig. 2). From an examination of the examples figured it will be observed
that they offer a considerable variation in form, and taken independently would
probably have been considered to represent fishes of distinct species.

The shoulder-girdle, together with bony masses of the branchial arches, are pre-
served on a slab obtained from the roof of the Lowmain coal seam near Newcastle,
now in the collection of W. Dinning, Esq., of that city. The bones of the scapular
arch to which the pectoral fins were attached (PL lxvii., fig. 1 a, b) occupy approxi-
mately a natural position. They are large, well-developed chondroid structures.
The scapular elements enumerated by Dr. Anton Fritsch* appear in this specimen to
be fused into one piece, no lines of demarcation being visible. The central portion
of the specimen is occupied by portions of the branchial arches, those on the left
side (c, Cu c2, cs, c4) being five in number, whilst on the right only four can be dis-
tinguished (d, di} d2, d3). A large and massive osseous element (e), partly projecting
and partly under the right scapular arch, is probably the hyo-mandibular. Scattered
over the slab are a number of the small stemmatoid ossicles (fig. 1 g) previously
described, which have been separated from the branchial arches. A peculiar bone
of a tripartite character occupies a position behind those mentioned above. It has
a length of 0*025 m. along its median axis, extending antero-posteriorly (fig. 1/),
at a distance of about one-fourth its length from the posterior extremity ; a branch
extends from each side, 0*01 1 m. in length; 0*005 in diameter at the base of
attachment, and diminishing to a point at the distal extremity. The derivation of
this bone is not quite clear, but it may have been attached to the occipital region
of the skull, and served as a base for the attachment of the cephalic spine.

Dr. Anton Fritsch describes the genera Pleur acanthus and Xenacanthus as
being possessed of seven gill arches.']' The principal evidence is afforded by a
specimen of Xenacanthus Decheni, Goldf., from the limestone of Oelberg, near
Braunau. The specimens of P 'leur acanthus are from the gas coal of Tremosa, near
Pilsen, and are more or less imperfect. Dr. Fritsch intimates that the true defi-
nition of the gill -arches is very difficult, and so far as the Pleur acanthus is con-
cerned he should not hold the evidence sufficient were it not for the proof that
the allied genus Xenacanthus could be shown to have had seven gill-arches on each
side. The first arch is weak ; the second to the fourth are similarly strong and
longer ; the fifth is shorter ; the sixth still shorter ; and the seventh is much thicker

* Fauna der Gaskohle, vol. iii., pt. i., p. 41, fig. 240 (woodcut).

f Fauna der Gaskohle, vol. iii., pt. i., p. 8, pi. xcm., fig. 3 ; pi. xciv., tig. 1 ; and p. 25, pi. xcvi.,
fig. 1, woodcuts 193 and 215.

718 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

and stronger, with a rough surface for the attachment of gill-rakers. M. Brongniart *
states that one of the specimens he described exhibited four grooves on the surface,
which probably represented the branchial arches. " Ce qui vient corroborer cette
opinion, c'est qu'il existe a leur base de petites rayons, visible sur tous les exam-
plaires et qui assure^nent ne sont autre chose que la charpente des branchies." In
the example now described the evidence appears to be with the French specimens,
a matter of some importance in relation to the classification of the genus.

A remarkable specimen in the collection of W. Dinning, Esq., of Newcastle,
also from the Lowmain coal seam, is represented on Plate lxvil, fig. 2. It
exhibits the bones comprising the upper surface of the cranium. The specimen
has been slightly crushed, and some of the lateral bones are displaced, as shown in
the figure. This specimen, along with others in his collection, has been most
carefully extricated from the matrix, and is a model of what may be done by
skilful and painstaking application. The bones of the median part of the skull are
undisturbed, whilst those occupying positions on each side have been subject to
lateral pressure and to some extent overlap each other. The bones, if they may
be so termed, or plates, are all of nearly uniform thickness, O003 m., and where
one has been forced over another, the plates are bent, and have received the
impress of the one above or below respectively, which appears to indicate very
clearly, that whilst the plates were sufficiently osseous to maintain their outward
shape, they were so plastic that their surface conformed readily to that of a
contiguous substance.

The central portion of the cranium is formed by a pair of subtriangular plates
joined by a straight median suture ; they are broad posteriorly, the anterior
margins being equal to half the breadth of the posterior ones ; these probably
represent the parieto-frontal bones (a). Behind these the occipital (b) occupies a
median position. At the junction of the frontals with the occipital there is a small
foramen ; and behind, the under surface is strengthened by a large ridge, more
or less circular, which probably afforded an attachment for the cephalic spine
(PI. lxvil, fig. 3). On each side the occipital, and attached to it and to the pos-
terior margins of the frontals, are a pair of plates (c) almost equal in size to
the occipitals ; and beyond these again, completing the posterior portion of the
cranium, are a pair of large plates exceeding in size either of the intermediate
ones. The plate to the right of the specimen is in its natural position ; the one
on the opposite side is squeezed forward and covers some of the smaller bones
forming the left portion of the cranium and also a part of the left frontal (fig. 2 d).
On each side the frontals, and parallel with their margins, are two smaller plates
(e,f) ; outside the anterior ones the orbits probably existed, but in this specimen

* Etudes sur le terrain houiller de Commentry, vol. ii., pt. 3, p. 9. 1888.

/. — Pleuracantlddce.

719

the lateral plates are squeezed towards the middle, so that the orbits are more a
matter of inference than certainty. Outside these again, and forming the lateral
margin of the cranium on each side, are two plates (g and h) represented approxi-
mately in their natural position in figure 2 «, and in figure 2 by the same letters.
Both the plates have been displaced, the anterior portion of each being pressed
under the preceding one. The form of each, however, is clearly seen on the
under surface of the specimen. Anterior to the frontals, and occupying a median
position, is a small hexagonal plate (%). To it are attached, besides the frontals,
the inner lateral plates (/), and in front, extending towards the snout, a pair of
large semi-rhomboidal plates (*, i). The posterior margins of these are joined
to the anterior margins of both the inner and outer lateral plates.

The cranium thus constituted is circular in front, expanding backwards and
forming a wide extension in the occipital region. The width across the latter
is about O'lOm., and the distance from the anterior extremity of the snout to the
outer margin of the occipital plate is 0*07 m.

The arrangement of the teeth is exhibited very clearly in a specimen in the
collection of Mr. George Wild, from the Thin Bed Coal at Burnley in Lanca-
shire (PI. lxviii., fig. 4). The teeth are comparatively small, their total length
being 0*007 m., of which the basal part occupies 0'002m., and the two principal
cusps 0"005m. The cusps are long, slender, divergent; between the two, the
median cusp ascends ; it is fully half the length of the principal ones, very
graceful and slender. Posteriorly at the base of the two principal cones there is a
large and prominent circular bulb ; the base of the tooth is antero-posteriorly
broader than it is between the two sides. More than fifty teeth are preserved in
this slab, and appear to be derived from both the upper and lower jaws. Two or
three rows are preserved in sequence. In one row there are six teeth, and in
another there are five (fig. 4). These are probably from the lower jaw. The
opposing teeth have the cusps pointing in the opposite direction and towards those
of the upturned ones of the lower jaw; they are not in rows, but more or less
disturbed ; they are smaller than the others, and the median cusp is longer in
proportion to the lateral ones, otherwise the teeth possess similar characters.
They are of the form described by Mr. A. Smith Woodward as Diplodus tenuis,
and as this is now shown to be associated with Pleur acanthus [Diplodus) gibbosus,
the Burnley specimens must also be included. Though in this specimen there is
not any appreciable variation in form, this may be due to the small portion of the
whole mouth which is preserved.

The specimen (PI. lxix.) is from the Atthey collection, presented to
the Newcastle Museum by Lady Armstrong, and exhibits the right ramus of
the lower jaws (a) with a portion of the left ramus connected to it at the
symphysial extremity (b). The length of the jaws is 0'36m. The greatest

TKANS. BOY. BUB. SOC, N.S. VOL. IV., PART XIV. 5 N

720 Davis — On the Fossil Fish Remains of the Coal Measures of the British Islands.

depth is near the posterior extremity where the jaw is 0-08 m., thence it
becomes less towards the symphysis, near which the jaw has a depth of 0*03 m.
Posteriorly the extremity consists of a concave articulatory surface (a') by
which it was attached to the palato-pterygoid. The substance of the jaw is
crushed, and appears to indicate that it was not sufficiently strong to resist
the pressure of the superincumbent matter. At the same time the fractured
surfaces show that it was by no means elastic. The anterior extremity was
probably of a firmer or more osseous consistence than the bulk of the jaw
behind ; but from the symphysis backwards the lower part of the jaw had a
similar texture, as indicated by the compact structure of the fractured surfaces.
The dentary surface was also of a firmly osseous substance, but the part of the
mandible between the two has the appearance of having had a thin osseous
covering, protecting an internal mass of more or less cartilaginous matter. The
surface of the bone is rugose, and where fractures have exhibited the internal
structure its chondroid character is clearly seen, the osseous centres presenting
very much the appearance of a piece of oolitic limestone, except that the colour is
black. The dentary surface is hidden by a large number of teeth ; the latter have
been displaced and are heaped together in a confused mass (e, c). The left
mandible is in a great part hidden by the teeth, the anterior portion (b) is exposed
compressed behind the right one. The lower jaws appear to have extended beyond
the upper one, but probably not to the extent indicated by the anterior extremity
of the upper jaw (d).

The teeth present considerable variety of forms ; they are, however, so indis-
criminately mixed that it is only possible to roughly estimate the position they
occupied in the jaws, and the difference in form due to their location. Besides
the typical examples hitherto regarded as Diplodus gibbosus, Ag., others with
more slenderly elongated cusps have been recognized by Mr. A. Smith Woodward
as identical with the teeth he has described as Diplodus tenuis.* Another form
presents very much the appearance of Pleuracanthus (Triodus) sessilis described
by Dr. Jordan ; f and the typical forms selected by Dr. Anton Fritsch^: as
representing the three genera, Orthacanthus, Pleuracanthus, and Xenacanthus, may
all be found in the teeth from the jaws of this specimen (PI. lxvi.).

On the lower part of the slab are two series of bones which are displaced, and
probably represent the branchial arches. They each consist of four or five
osseous elements connected together and having a semicircular arrangement. The
bones are similar in character to those of the jaws, consisting of closely impacted

* Catalogue of the Fossil Fishes in the British Museum, pt. i., p. 11, pi. vi., figs. 2-4.
f Neues Jahrb., p. 843. 1849.

J Fauna der Gaskohle und der Kalksteine der Permformation Bohmens, vol. ii., pt. iv., p. 99, wood-
cuts, figs. 173 a, 174 c, and 175 b. 1889.

/. — Pleuracanthidce.

721

osseous centres in a cartilaginous framework. They are larger at the proximal
end of the series and diminish in diameter towards the opposite one (cf. i., n.,
nr., iv.). They may be compared with the specimens figured by Dr. Fritsch of
the branchial arches of Orthacanthus Kounoviensis, Fr., a large species comparable
with this one, in which the branchial arches are composed of a series of four or
five separate semi-osseous parts.*

Separated from, but near the branchial arches, are a number of small denticu-
lated ossicles, which were probably attached to the gill-arches. They consist of a
series of small, sharp denticles, attached to a broad base. The arrangement of
the denticles varies in nearly every example. Those represented on PI. lxx.,
figs. 2, 3, are from the slab now described ; others have been found in the
Coal Measures of Staffordshire, Lancashire, and Yorkshire.

The example represented by fig. 4 was found associated with the remains of
Pleuracanthus, near Wigan ; it has seven irregularly disposed denticles attached
to a more or less triangular base. The denticles are elongated, smooth, and
pointed. Mr. G. Wild has examples which he has collected from the Middle Coal
Measures of Lancashire, one of which, with 16 or 17 prongs, is represented by
fig. 5.

Mr. John Ward has found a considerable number of similar objects in the
Eagmine Ironstone Shale, at Fenton in Staffordshire, associated with teeth and
other remains of Pleuracanthus (figs. 6—10). They exhibit a great variety in the
form and arrangement of the denticles, but notwithstanding the difference in the
number of the denticles and the varied manner in which they are attached to
the base, there is a general similarity of construction which appears to indicate
uniformity of purpose.

Similar objects were found in the fish-bed of the Upper Burlington Limestone
of the Lower Carboniferous Eocks of America. Messrs. St. John and Worthen,t
who described the remains, considered them of so anomalous and withal variable
character as seemingly to indicate representatives of several distinct though
closely-allied generic groups. Subsequently they were regarded as the teeth of
a single genus, which was named Stemmatodus, and the so-considered teeth were
divided into several species. They were supposed to have occupied the tongue
or back part of the mouth of fish similar to Dipterus or Ceratodus. Mr. A. Smith
Woodward % regards the specimens described by Messrs. St. John and Worthen,
as well as those from Fenton in Staffordshire, as the dermal tubercles of some of
the Elasmobranchs, and this opinion is accepted by Mr. J ohn Ward. §

* Op. cit., pt. iv., p. 108, pi. lxxxtv.

f Palaeontology of Illinois, vol. vi., p. 328. 1875.

% Catalogue Foss. Fishes, vol. i., p. 248. 1889.

§ Trans, of North Staffordshire Inst, of Min. and Mech. Engineers, vol. x., p. 153, pi. n., fig. 22. 1890.

5 N 2

722 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Dr. Anton Fritsch* discovered and described a number of similarly denti-
culated fossil remains attached to the gill-arches of Pleuracanths in the Gaskohle
of Bohemia. A comparison of the figures of the specimens described by
Dr. Fritsch with those now figured from the English Coal Measures will at once
demonstrate the identity of their origin and purpose.

The specimen from the Lowmain coal seam at Newsham, represented on
PL lxx., is the head of a large specimen, much crushed and displaced, but
exhibiting some interesting features. The mass preserved on the slab is 0*37 m.
from front to back, and 0*27 m. across the head. A large spine of Pleuracanthus
Icevissimus, Ag., extends from the centre of the slab, apparently the middle of the
head; it is 0'17m. in length, but the anterior part of the spine is absent. The
base of the spine, extending to the part on which the denticles are present, is
about 0*14 m. in length ; and had the whole of the spine been preserved, a com-
parison of this with other perfectly preserved specimens, indicates a length of
0*22 m. The base of the spine has a diameter of O013m., and higher, where the
denticulated surface begins, the diameter is 0*01 m. The surface of the spine
has the striated appearance characteristic of the species, and the denticles are
similar to those already described as P. Icevissimus. As to the manner in which
the spine was attached to the cranium, this specimen does not give much infor-
mation ; there are a number of semi-osseous structures in immediate proximity to
the base of the spine, and to these it may probably have been attached, but the
method of its attachment is not shown.

Immediately below, and almost parallel with the spine, there extends the right
ramus of the lower jaw, crowded with teeth ; it originally extended beyond the
margin of the slab, but is imperfect. The teeth are similar to those exhibited on
PI. lxix., and are those known as Diplodus gibbosus, Ag. The vertical arrange-
ment on the alveolar surface is well shown ; there were four teeth, possibly
more, in each row, which lie closely parallel to each other. Nineteen or twenty
vertical rows of teeth may be distinguished, and the extremity of the jaw
being absent the total number would be larger. Besides the teeth of this jaw,
there are numerous others scattered over the slab intermingled with masses of
bony structure representing the semi-osseous cranial plates. The latter are too
much disturbed to allow their relative natural position to be made out.

The occurrence of the spine, Pleuracanthus Icevissimus, Ag., and the teeth,
Diplodus gibbosus, Ag., on this specimen is of importance, because it removes any
doubt as to the identity of the series of specimens obtained from the Lowmain
coal seam.

The specimen figured on PI. lxxi. is from the collection of W. Dinning, Esq.,

* Op. cit., p. 105, pi. lxxx., figs. 1-12, &c.

I. — Pleuracan thidce.

723

of Newcastle-on-Tyne. It exhibits a part of the body and the posterior portion
of the head, with a number of teeth. Several detached cranial plates (b, b) and a
large bone (a), which probably represents the lower jaw, are present. Associated
with these are many spinous and interspinous bones. The latter are long, straight,
and slender ; of a dense bony structure, apparently similar to that of the spines.
The spinous apophyses are much dilated at the proximal extremity, which was
attached to the sheath of the notochord (c, c). The teeth are those of the so
named Diplodus gibbosas, medium size ; the lateral prongs are slender and
attenuated, and the median denticle is also comparatively long.

The long interspinous rays are frequently met with in the coal fields where
remains of Pleuracanthus occur. On PI. lxxi. two interspinous rays are figured,
natural size; one measuring 0*12 m. and the other 0*125 m. Along with these
were found examples of the surapophyses, three of which are represented on the
same Plate (fig. 4). They vary from 0*01 to 0*015 m. in length.

A specimen exhibiting the left pectoral fin is represented on PI. lxv., fig. 2. The
part preserved is O'lm. in length, and comprises a portion of the pterygium,
with a mass of fin-rays attached to its outer border, and a smaller series on its
inner one. The constitution of the central axis is not well preserved. The outer
series of fin-rays number in this specimen twenty-two or twenty-three ; the
longest are 0*09 m. in length, and each is divided into about ten parts articulated
together. The articulated segments are longest in the median part of the ray,
shorter towards the axis, and pointed at the distal extremity ; they have an average
diameter of 0*002 m. The rays are semi-osseous, and have the usual granular
ajDpearance. The fin-rays springing from the inner surface are shorter and more
slender ; they are little more than half the diameter of those on the opposite one.

The form and constitution of this fin differ considerably from those described
by M. Brongniart* and Dr. Fritsch.f There are a larger number of rays, and
each is divided by a greater number of articulations. The rays attached to the
segments of the pterygium, near the basal extremity, are proportionately longer
than those of the French or Bohemian fishes.

The specimen figured is from the cannel coal at Tingley, in the West Eiding
of Yorkshire, and is in the collection of the writer.

* Etudes terr. houil. Commentry, p. 25, pi. iv.

f Fauna der Gaskohle Bohmens, vol. ii., pt. iv., p. 99.

724 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Pleuracanthus lsevissimus, Agassiz.
(PL lxxil, figs. 1-9.)
I. — Spines.

Pleuracanthus laevissimus, . Agassiz, L., 1837, 11 Poiss. foss.," vol. iii., p. 66,

pi. xlv., figs. 4, 5.

Pleuracanthus planus, . . Agassiz, L., 1843, torn, cit., p. 177 (name only).

Pleuracanthus laevissimus, . Morris, J., 1854, " Cat. Brit. Foss.," p. 339.

Pleuracanthus laevissimus, . Barkas, T. P., 1873, "Coal Meas. Palaeont.,"

p. 17, pi. I., figs. 14-16.

Pleuracanthus laevissimus, . Ward, J., 1875, " Proc. N. Staffs. Nat. Field

Club," p. 225.

Pleuracanthus laevissimus, . Davis, J. W., 1880, "Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 325 (woodcut).

Pleuracanthus pulchellus, . Davis, J. W., 1880, he. cit., vol. xxxvi., p. 327,

pi. xii., fig. 2.

Pleuracanthus planus, . . Davis, J. W., 1880, loc. cit, vol. xxxvi., p. 329.

Pleuracanthus elegans, . . Traquair, R. H., 1881, "Geol. Mag.," ser. u.,

vol. viii., p. 36.

Pleuracanthus lsevissimus, . Traquair, R. H., 1888, loc. cit., ser. in., vol. v.,

p. 101.

Pleuracanthus laevissimus, . Etheridge, R., 1888, "Foss. Brit. Islands."

Pleuracanthus lsevissimus, . Woodward, A. S., 1889, " Cat. Foss. Fishes

Brit. Mus.," pt. i., p. 5.

Pleuracanthus elegans, . . Woodward, A. S., 1889, loc. cit., pt. i., p. 9.

Pleuracanthus laevissimus, . Ward, J., 1890, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 134, pi. m.,
fig. 8.

Pleuracanthus laevissimus, . Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 154.

Pleuracanthus elegans, . . Woodward & Sherborn, 1890, loc. cit, p. 154.

I. — Pleuracan thidce.

725

Diplodus gibbosus,

Diplodus gibbosus,

Diplodus gibbus, .
Diplodus gibbosus,
Diplodus gibbosus,
Dittodus parallelus,

Dittodus divergens,
Ochlodus crassus,
Aganodus apicalis,
Aganodus undatus,
Pternodus productus,
Diplodus gibbosus,

Pleuracanthus (Diplodus) gib-
bosus,
Diplodus gibbosus,

Diplodus gibbosus,
Diplodus gibbosus,

II.— Teeth.

Diplodus gibbosus, Agassiz.

Binney, E. W., 1841, "Trans. Manchester Geol.

Soc.," vol. i., p. 169, pi. v., figs. 17, 18 (name

and figure only).
Agassiz, L., 1843, " Poiss. foss.," vol. iii., p. 204,

pi. xxir. b, fig. 1 (non figs. 2—5).
Garner, R. 1844, "Nat. Hist. Staffs.," pi. e., fig. 11.
Williamson, W. C, 1851, " Phil. Trans.," p. 680.
Morris, J., 1854, " Cat. Brit. Foss.," p. 325.
Owen, P., 1867, " Trans. Odontol. Soc," vol. v.,

p. 325, pi. i.
Owen, R., 1867, torn, cit., p. 334, pi. n.
Owen, R., 1867, torn, cit., p. 346, pi. v.
Owen, R., 1867, torn, cit., p. 359, pi. ix.
Owen, R., 1867, torn, cit., p. 362, pi. x.
Owen, R., 1867, torn, cit., p. 363, pi. xi.
Hancock, A., & T. Atthey, 1870, "Nat. Hist.

Trans. Northumb. and Durham," vol. iii.,

p. 111.

Ward, J., 1875, " Proc. N. Staffs. Nat. Field

Club," p. 244.
Ward, J., 1889, " Trans. N. Staffs. Inst. Mining

and Mech. Engineers," vol. x., p. 138, pi. n.,

fig. 3.

Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 10.
Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 66.

Diplodus tenuis, A. S. Woodward.

Diplodus gibbosus, . . Agassiz, L., 1843, " Poiss. foss.," vol. iii., p. 204,

pi. xxn. b, figs. 2—5.

Pleuracanthus (Xenacanthus) Salter, J. W., 1861, "Foss. S. Welsh Coalfields"
gibbosus, (Mem. Geol. Survey, Iron Ores Gt. Britain,

pt. in.), p. 224, pi. i., fig. 10.

726 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Diplodus gibbosus, . . Barkas, T. P., 1873, " Coal Meas. Palseont.,"

p. 16, pi. i., figs. 6, 7, 9-13.
Diplodus gibbosus, . . Barkas, W. J., 1874, " Monthly Rev. Dental

Surgery," vol. ii., p. 346, figs. 1-4.
Diplodus tenuis, . . . Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. I., p. 11, pi. vi., figs. 2-4.
Diplodus tenuis, . . . Ward, J., 1889, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 140, pi. n.,

fig. 1.

Diplodus tenuis, . . . Woodward & Sherborn, 1890, "Cat. Brit. Foss.

Verteb.," p. 67.

III. GlLLRAKERS.

Stemmatodus, St. John & Worth en.

Stemmatodus, . . .St. John & Worthen, 1875, " Palseont. Illinois.,"

vol. vi., p. 328.

Stemmatodus, . . . Woodward, A. S., 1889, " Cat. Foss. Fishes,"

vol. i., p. 245.

Stemmatodus, . . . Ward, John, 1890, " Trans. N. Staff. Inst. Min-
ing and Mech. Engineers," vol. x"., p. 153,
pi. ii., fig. 22.

Stemmatodus, . . . Woodward & Sherborn, 1890, " Brit. Foss.

Verteb.," p. 188.

The teeth of Pleuracanthus Icevissimus, Ag., vary greatly in form ; there are
two principal cones, circular, or more or less compressed, with or without lateral
cutting edges, sometimes striated. The cones are divergent, and frequently
exhibit a slightly sygmoidal curvature. Between the two outer denticles is a
smaller intermediate one, which may be short and compressed or comparatively
long and slender. On the posterior surface behind the smaller intermediate
denticles is a "button," which forms the seat on which the anterior part of the
base of the succeeding tooth rested. The "button" is of irregular size, some-
times prominent, at others scarcely discernible, which is probably due to the
different relative positions occupied by the teeth. Base broad, extending
backwards, inferior surface more or less flattened.

The spines of Pleuracanthus Iwvissimus are straight, broad at the base, and
tapering upwards to a more or less pointed apex ; compressed antero-posteriorly,

/. — Pleuracan thidce.

727

but towards the distal extremity circular in section ; surface smooth. Double
row of reflexed, acuminate denticles, one on each lateral margin and extending
along two-thirds the length of the spine. An internal cavity extends from the
base upwards. Towards the distal end the internal cavity is small, lower it is
large, and the walls of the spine are thin ; they are frequently crushed. The base
of the spine, when preserved, is contracted at the extremity, and the portion
embedded in the integuments was not proportionately large. The large groove
stated by M. Agassiz* to extend along the inferior surface of the spine does not
always exist in the specimens examined ; the appearance may have been due to
crushing. The only other record of a similar groove is in the spines of Pleuracanthus
parallelus, Fr.,t from the gas-coal of Nyran, in Bohemia.

The base of the spine represented on PI. lxxii., fig. 1, is worthy of note. It
is widely and rapidly expanded, which is probably, in part at any rate, due to
crushing; but this will not account for the whole of the expansion.

The spines of this species vary considerably in size ; the largest are about
0*3 m. in length ; one specimen from Dalkeith, in the British Museum, has a
length of 0*35 m. (PI. lxxii., fig. 2). The specimen from Dudley, figured by
Agassiz, is 0*22 m. ; % others from the Lower and Middle Coal Measures of the West
Riding of Yorkshire attain the same length, whilst the graceful and well-preserved
examples from the Staffordshire coal field are mostly about 0*15 m. in length.

Associated with the larger spines of the cannel coal, in the Middle Coal
Measures of the West Riding at Tingley, there are a number of small spines, which
have been previously described as Pleuracanthus pulchellus § ; they are generally
the same length, about, 0*04 or 0*05 m. Since describing these exquisitely beautiful
little spines, when it was suspected that they might be the spines of immature
fishes of P. Icevissimus, the discovery of other examples has led to the conviction
that such is their proper location, and that the difference in the number of lateral
denticles, there being twenty on each side of the small examples against fifty in the
large ones, may be due to the respective ages of the two, and increased growth of
denticles as the spine has matured. The small imperfect spine named, but not
described, by Agassiz, || Pleuracanthus planus, originally in the collection of Sir
Philip Egerton, and now in the British Museum, is about half-an-inch in length,
the basal end absent ; the exposed surface is smooth and flat, and six or seven
strong denticles extend along each lateral margin. It is recorded as coming from

* Poiss. foss., vol. iii., p. 66, pi. xlv., fig. 5.

f Fauna der Gaskohle unci der Kalksteine der Permformation Bohmens, Band iii., Heft. 1, pis. xci.
and xcrv.

I Poiss. foss., vol. iii., pi. xlv., fig. 6.

§ Quart. Joum. Geol. Soc, vol. xxxvi., p. 327, pi. xn., fig. 2.
|| Op. tit., p. 177.

TBANS. EOT. DUB. SOC, N.S, VOL. IV., PAET XTV. 5 O

728 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Leeds, and was doubtless from the same locality as those mentioned above, and
with them, may be included in this species.

The specimens described by Dr. R. H. Traquair* as Pleuracanthus elegans bear
a close resemblance to the small spines from Tingley, originally described as a
separate species but now included in Flew 'acanthus Icevissimus. The form, size,
and number of lateral denticles is almost identical with the Tingley specimens,
and if the latter are the young examples of this species, there can be little difficulty
in assigning the small spine described by Dr. Traquair to this species also. The
type is described as two and a-half inches in length, from the Blackband Ironstone
of Borough Lee, near Edinburgh, and in the collection of R. Kidston, Esq., of
Stirling.

The spines of Pleur acanthus Icevissimus, Ag., from the cannel coal at Tingley
are almost cylindrical in section as compared with those from the Fenton and
Longton localities in Staffordshire. The latter are compressed antero-posteriorly,
and oval in section ; the spines from the Lowmain Seam near Newcastle are
similar to those from Staffordshire. The lateral denticles on the Yorkshire
specimens are larger and more widely separated than those of the other localities
named (see PI. lxxii., fig. 3). The number of denticles on the spines from the
several localities offers considerable variety. The specimens found at Tingley, at
Fenton, and the one from Newsham, represented by fig. 6 have between fifty-five
and sixty denticles on each side, whilst the specimen, fig. 7, from the same
locality, has only thirty -two, and the one from Shattleston, fig. 8, near Glasgow,
has forty on each margin. The smallest examples, about two inches in length,
average about eighteen or twenty on each side. Presuming that all these specimens
are of one species, it would appear that the number of denticles increases with the
age and size of the spine.

The occurrence of a large number of species represented by an abundance of
specimens of each in the cannel coal of the West Riding of Yorkshire "f appears to
indicate that Pleuracanthus flourished and attained its greatest numerical develop-
ment in fresh water. The cannel coal extends over a considerable area, in patches
two or three miles in diameter, thickest in the centre and thinning off towards the
edges, proving that it was accumulated in a series of lakes or lagoon-like depres-
sions. The coal is a very pure carbonaceous substance with only 2 or 3 per cent,
of earthy matter, and attains a maximum thickness of about two feet. To accu-
mulate this large mass from the gradual decay of the leaves and spores shed by
the plants growing in or about the lagoons would take a long time, and indicates
a period of great quiet. Occasionally a stream ran through the lagoons bearing
fine mud, and the latter settled along with the vegetable matter, and together

* Geol. Mag., ser. n., vol. viii., p. 36.

f Quart. Journ. Geol. Soc, vol. xxvi., p. 56.

I. — Pleuracan thiclw.

729

produced an impure coal, locally termed " hubb." The fish -remains are found
indiscriminately in the pure cannel and the hubb, and associated with them are
myriads of Unios and fresh-water shells. The latter probably served as food for
the Pleuracanths, whilst the Coelacanths, which also existed in very large numbers,
were probably vegetable feeders. Large spines of Ctenacanthus and Gyracanthus are
not uncommon, and there can be no doubt that these sharks existed in the same
lagoons and preyed on the smaller fish : the strong, sharply-pointed barbs with
their lateral recurved rows of hooklets of the Pleuracanths would serve as an
admirable defence against their more powerful adversaries.

A peculiar and abnormal specimen of P. Icevissimus was found by Mr. George
Wild, of Bardsley, in the shale forming the roof of the coal at the Arley Mine,
Burnley. The specimen is imperfect. The part preserved is 0*105 m. in length,
and consists of the middle part of a spine. The base and the point are wanting ;
the spine is oval in section, and denticles extend along each lateral margin as in
the typical examples of the species. This one differs, however, from the types in
several particulars. On one side of the spine there are three rows of denticles
instead of one (PI. lxxii., fig. 4), and on the opposite side there are two rows in one
part of its length, whilst on the remainder there is only a single row. The latter
margin is free from denticles for a distance of 0*045 m. from the basal end; whilst the
margin with three rows extends the whole length of the existing part of the spine.
In the shorter row there are twenty-one denticles on the median lateral line,
and from the fourth to the tenth denticle the row is double (fig. 5). The denticles
are strong and broad at the base; the apex curved backwards; and a groove
extends along their base parallel with the length of the spine. There are thirty-
three denticles in the median row on the opposite side, flanked on the one side by
thirty-two denticles, smaller but of similar form, and on the other by twenty-three
denticles extending from the basal end, but disappearing towards the distal ex-
tremity. The structure of the spine has the same dense character possessed by
others of this species, and in other respects it is similar. The presence of the extra
rows of denticles is apparently only an abnormal aberration from the type.

M. Brongniart* states that the small spine of Pleuracanthus pulchellus, Davis,
from the cannel coal of Tingley is very nearly related to the spine of Pleura-
canthus Gaudryi, Brong., from the Upper Coal Measures of Commentry in France ;
and the spine figured and described by Dr. Fritsch "j* as Pleuracanthus ovalis
does not appear to differ in any essential respects. It is similar in size to
P. elegans, Traq., and P. pulchellus, Davis ; it has about twenty denticles on
each side, and in other respects resembles the spines of immature examples of
P. Icevissimus, Ag.

* Etudes sur le terrain houiller de Commentry, Fauna Ichthyologique, pt. I., p. 33. 1888.
f Fauna der Gaskohle Bohmens, vol. iii., pt. i., p. 13, pi. xci., figs. 9, 10.

5 0 2

730 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

The spine of Pleuracanthus (Elbergensis, Fr.,* is very much like the medium-
sized species of P. Icevissimus, Ag., from the Coal Measures near Glasgow. They
are the same length, and each side of the spine is armed with about forty
denticles. The spine of Xenacanthus Decheni, Goldf.,"f also resembles P. Icevissimus,
Ag., both in form and size, and the number of denticles in each is the same.

Formation and Locality. — Lowmain Coal Seam, Newsham, Northumberland;
Cannel Coal, Tingley ; Better-bed Coal, Yorkshire ; New Ironstone (Ragmine)
Fenton ; Arley Mine, Burnley ; Shattleston, near Glasgow.

Fx coll. — Museum of Natural History, Newcastle-on-Tyne ; J. W. Davis,
Halifax ; John Ward, Longton ; James Thomson, Glasgow ; W. Dinning, New-
castle-on-Tyne ; George Wild, Bardsley.

Pleuracanthus robustus, Davis.

(PI. lxxii., figs. 10-14.)

Pleuracanthus robustus,

Pleuracanthus robustus,
Pleuracanthus robustus,

Pleuracanthus robustus,

Pleuracanthus robustus,

Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 330, pi. xii., fig. 5.
Etheridge, R., 1888, "Foss. Brit. Islands."
Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 7.
Ward, J., 1890, " Trans. N. Staffs. Mining and

Mech. Engin.," vol. x., p. 136.
Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 155.

Spines : the largest examples occur at Tingley ; they are imperfect, the base
being absent. The part preserved is 0*09 m. in length ; if perfect it would pro-
bably have measured 011 m. The surface is covered with fine longitudinal
striations. The diameter in the median part is 0'008 m., whence it tapers to a
point at the distal extremity. The basal extremity is also considerably less in
diameter than the median part. An internal cavity occupies rather more than
one-third the diameter at a distance of 0'09 m. from the point. The spine is very
slightly curved. In section the superior surface is rounded in the upper half, and
more or less triangular nearer the base ; the inferior surface is slightly curved, and
forms a longitudinal median ridge. The angles formed by the outer edges of this

* Op. cit., p. 15, pi. xcvi., fig. 3.

f Beit. Vorwelt Fauna, p. 23, pi. v., fig. 9, 1847 ; and Fritsch, op. cit., pi. xcviii., fig. 2.

/. — Pleuracan thidce.

731

surface with the sides of the spine are armed with a series of denticles. The den-
ticles extend from the apex a distance of 0*04 m. They are large, strongly implanted,
closely-set, recurved, and sharply pointed ; about twenty on each side. The upper
surface of the denticles, i. e. the one having the greatest curvature, is produced so
as to form a miniature carina or keel, smooth and sharp (PI. lxxii., figs. 10, 11).

Since this species was described in 1880, specimens have been found in other
localities. One of these, discovered by Mr. John Ward, in the Knowles Ironstone
Shale, at Fenton, is of peculiar interest (fig. 12). The dorsal or inferior surface is
exposed ; the spine is complete, though somewhat fractured in the median part. It
is smaller than the Tingley specimens, being 0*086 m. in length. The attenuation
of the basal part of the spine, which was implanted in the integument of the fish,
is well shown. The walls are comparatively thin and hollow ; they extend to
the basal extremity only on the anterior surface ; the internal cavity instead of
being terminal is open a distance of 0*012 m. along the inferior surface, the walls
gradually enfolding it, as shown in the figure. The number of denticles is the same
as in the Tingley specimen.

This species has also been found in the Lowmain coal seam at Newsham,
and a specimen is figured from Mr. Atthey's collection at the Museum at Newcastle.
It is complete ; 0*087 m. in length. The lateral surface is exposed, with one row
of denticles, extending a distance of 0*03 m. from the point ; they are fourteen
or fifteen in number, and of a similar character to those already described
(PI. lxxii., fig. 13).

Spines in all respects similar to the latter are found in the cannel coal at
Tingley, but of much smaller size. They appear to have belonged to fishes which
were not mature (fig. 14).

Spines belonging to the fossil fish named by Dr. Fritsch Orthacanthus pinguis,
Fr.,* bear a close relationship to this species ; they are larger in size, but the robust
form and the arrangement, position, and number of the denticles resemble the
spines of P. robustus, Davis.

Formation and Locality. — Middle Coal Measures, Cannel Coal, Tingley,
Yorkshire ; Deepmine and Knowles Ironstone Shale, Fenton and Longton,
Staffordshire ; Lowmain Coal, Newsham, Northumberland ; Carluke.

Ex coll. — James W. Davis, Halifax ; J. Ward, Longton ; Museum of Natural
History Society of Northumberland and Durham, Newcastle-on-Tyne ; British
Museum (Nat. Hist.).

* Fauna der Gaskohle, vol. ii., pt. iv., p. 109, pi. lxxxvii., figs. 3, 4, 6.

732 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Pleuracanthus Wardi. Davis.
(PI. LXXII., fig. 15.)

Pleuracanthus Wardi, . . Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 334, pi. xn., fig. 6.

Pleuracanthus Wardi, . . Etheridge, R., 1888, "Foss. Brit. Islands."

Pleuracanthus Wardi, . . Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 10.

Pleuracanthus Wardi, . . Ward, J., 1890, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 136.

Pleuracanthus Wardi, . . Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 155.

Spine: imperfect; the part preserved consists of the median part, 0*15 m. in
length. The base and upper portion are absent. It is 0*012 m. diameter nearest
the base, and diminishes gradually to 0*007 m. at the part preserved nearest to
the point. The front of the spine is rounded and striated longitudinally ; the
posterior surface is armed with a double row of denticles, forming continuous
ridges, and separated only by a narrow groove. The denticulated surface extends,
a distance of 0*09 m. ; the denticles are short and obtuse, probably due to abrasion.
The spine in transverse section is depressed on each side of the lines of denticles
towards the median lateral line, which is somewhat angular. The spine is arched
towards the posterior surface, and the internal cavity is large in proportion to
the size of the spine.

This spine more nearly approaches the characters of Pleuracanthus cylindricus,
Ag., than any other, and it has been suggested by Mr. Ward and others that its
separation from that species may be conjectural. After a careful reconsideration
of the specimens, however, I am still of opinion that its long slender form and
decided curvature, together with the closely approximating lines of denticles
forming continuous ridges, and the form of the spine in section, separate it with
sufficient distinctness from the stronger cylindrical spine and the well-defined
denticular arrangement of P. cylindricus.

Formation and Locality. — Ragmine Ironstone Shale, Fenton, Staffordshire.

Ex coll. — John Ward, Longton.

2". — Pleuracanthidce.

733

Pleuracanthus undulatus, sp. nov.
(PI. lxxii., fig. 16.)

Spine: straight, 0-13 m. in length, O'Ol m. in diameter at the base, gradually
diminishing to the pointed apex. Section of spine, midway and higher, circular ;
base somewhat crushed, but apparently oval. Upper posterior surface has two
rows of denticles, which are large, broad at the base, blunt and widely separated.
The denticles are placed diagonally, those of one row being slightly in advance
of those of the other. At a distance of 0*03 m. from the apical extremity, the
two rows are separated by a space equal to one-half the diameter of the spine,
and the interval between two denticles in the same row is 0*07 m. Both the
distances, between the two rows, and between the individual denticles diminish
gradually towards the point.

This spine is clearly distinguished from others previously described, by the
large and widely separated posterior denticulation. It was found by Mr. George
Wild, of Bardsley, and presented to the Manchester Museum.

Formation and Locality. — Thin-bed Coal, Fulledge Colliery, Burnley.

Ex coll. — Mr. G. Wild : Manchester Museum, Owens College.

Pleuracanthus tenuis, Davis.

Pleuracanthus tenuis,

Pleuracanthus tenuis,
Pleuracanthus tenuis,

Pleuracanthus tenuis,

(PI. lxxii., fig. 17.)

Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"
vol. xxxvi., p. 327, pi. xii., fig. 1.

Etheeidge, E., 1888, " Foss. Brit. Islands."

Woodwaed, A. S., 1889, " Cat. Foss. Fishes Brit.
Mus.," pt. i., p. 10.

Woodwaed & Sheeboen, 1890, " Cat. Brit. Foss.
Verteb.," p. 155.

Spine: long and slender, imperfect; length preserved is 0*12 m.; diameter
0-005 m. ; basal part circular in section ; upper part more or less angular.
Along each lateral margin for a distance of 0-07 m. there is a row of denticles,
about eighteen or twenty in number, with bluntly-rounded points tipped with
enamel. The spine is slightly curved. There is an internal canal, wide near the
base, but converging higher up, and extending through the whole of the length.

734 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

This species is peculiar from its great length in proportion to the diameter.
Its curved form distinguishes it from all other species, which have the denticles
arranged on the directly opposing lateral surfaces of the spine.

Formation and Locality. — Bone-bed, Better-bed Coal, Clifton, near Halifax
(Lower Coal Measures).

Ex colL — James W. Davis.

Pleuracanthus denticulatus, Davis.
(PI. lxxii., figs. 18-20.)

Pleuracanthus denticulatus, . Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. r334, pi. xn., fig. 7.

Pleuracanthus denticulatus, . Woodward, A. S., 1889, " Cat. Foss. Fishes,

Brit. Mus." pt. i., p. 9.

Pleuracanthus denticulatus, . Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 154.

Spine: base wanting; length 0*055 m. ; distinctly curved ; lateral and anterior
face smooth ; circular in section ; the posterior surface is flat, with two rows of
denticles separated by a distance equal to one-half the diameter of the spine.
The denticles are small, closely set together, broad and strongly attached at the
base, contracting suddenly, and forming a carinated apex, pointing towards the
base of the spine.

There are forty-five denticles on each side on the length preserved. A some-
what large central cavity extends towards the apex.

This specimen is from the Bone-bed above the Better-bed coal, and from that
locality is unique ; other specimens have been found in the shale above the cannel
coal at Tingley, which differ little from the type ; they have similar closely set
strong denticles. The sides are somewhat compressed, and towards the base have
slight striae. It is possible that if the base of the Bone-bed specimens were pre-
served, its surface might be ornamented in the same way. The lower part of the
spine is thin, and the internal cavity large ; the walls expanding towards the base.
A perfect example would probably be 0*09 m. in length. They are composed of
a dense bony substance (fig. 18).

This species differs from all the others obtained from the West Riding coal
field in its arched form, and close, peculiar denticulation. Pleuracanthus arcuatus,
Newberry,* afterwards described and figured by the same author as Orthacanthus

* Proc. Acad. Nat. Sci., Philadelphia. 185G.

/. — Pleuracanthidce.

735

arcuatus, Newb.,t is a spine closely allied to the one now described. It was found
associated with, and buried in, an "ill-defined mass of granular material, which
represents in the cannel coal the partly- ossified cartilage that composed the hard
parts of the head of Diplodus. With them are also groups of Diplodus teeth still
attached to the jaws." The spines were arched and tapering, and striated on the
surface, and the posterior face flattened, or raised into a low ridge along the
median line, and on each side of it a row of closely set acuminate depressed
hooks. The hooks or denticles of the Linton species are apparently longer and
more numerous than those from the Better-bed coal, but they closely resemble the
Tingley specimens, especially in the striation of the surface of the spine. The
Linton spines are from cannel coal.

P. denticulatus has been found in the Lowmain coal seam at Newcastle. A
specimen almost perfect is 0*085 m. in length : the denticulated posterior surface
extends from the apex 0-04 m., and is armed with a double row of barbs, about
forty in number, on each side. The basal half of the spine is uniform in diameter,
except quite near the base, which is smaller. The surface is covered with minute
longitudinal striae, similar to that of the Yorkshire specimens (fig. 19).

A specimen in the collection of Mr. George Wild, from the shale above the
two-feet coal at Bardsley, in Lancashire, is identical with this species. The base
of the spine is not preserved, the upper portion is slightly arched backwards, and
a row of denticles, about forty in number, are exposed, extending a distance of
0*05 m. from the point (fig. 20).

Formation and Locality. — Bone-bed, Better-bed Coal, Clifton and Lowmoor ; and
Cannel Coal, Tingley, in the West Eiding of Yorkshire ; Lowmain Coal, Newsham,
Northumberland ; Two-feet Coal, Bardsley, Lancashire.

Ex coll. — James W. Davis, Halifax ; Museum of Natural History Society of
Northumberland and Durham, Newcastle-on-Tyne ; George Wild, Bardsley.

Pleuracanthus Howsei, sp. nov.

(PI. LXXIL, fig. 21.)

Spine: length, 0*12 m.; diameter, 0*006 m., near the base, from which the
diameter gradually diminishes and terminates in a finely-pointed apex. Spine is
slightly curved, more or less ovoid in section, with a double row of denticles
extending along the posterior surface; from the distal extremity the denticles
extend a distance of 0*05 m. The denticles are twenty-eight in each row; short,

f Palseont. Ohio, vol. L, p. 332, pi. xl., fig. 4, 1873.

TKANS. EOT. DUB. SOC, N.S. VOL. IV., PAET XIV.

736 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

blunt, about their own diameter apart. The two rows are comparatively close
together. The base of the spine is preserved ; it is hollow, with thin tapering
walls. The cavity appears to have been terminal. The surface of the spine is
finely striated.

This spine, which it is suggested should be specifically designated Pleura-
canthus Hoivsei, may be distinguished from F. denticulatus, Davis, to which it
bears a general resemblance, by the smaller number of its denticles — it having
twenty-eight, whereas P. denticulatus has forty-five on a spine somewhat smaller
than the one now described. The denticles in this species are blunt and rounded,
in the other they are long, recurved and acuminate.

Formation and Locality. — Lowmain Coal Seam, Newsham, Newcastle-on-Tyne.

Ex coll. — Museum of the Natural History Society of Northumberland and
Durham, Newcastle-on-Tyne.

Pleuracanthus alatus, Davis.

(PL lxxiii., figs. 5-13).

Pleuracanthus alatus,

Pleuracanthus alternidentatus,
Pleuracanthus attenuidentatus,

Pleuracanthus altus,
Pleuracanthus alatus,

Pleuracanthus alternidentatus,
Pleuracanthus alatus,

Pleuracanthus alatus,

Pleuracanthus alternidentatus,

Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 329, pi. xn., fig. 4.
Davis, J. W., 1880, loc. cit., p. 328, pi. xn., fig. 3.
Etheeidge, R., 1888, " Foss. Brit. Islands," pt. i.,

p. 337 (misprint).
Etheridge, R., 1888, loc. cit., p. 337 (misprint).
Woodward, A. S., 1889, "Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 9.
Woodward, A. S., 1889, loc. cit, p. 9.
Ward, J., 1890, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 136.
Woodward & Sherborn, 1890, "Cat. Brit. Foss.

Verteb.," p. 153.
Woodward & Sherborn, 1890, loc. cit., p. 153.

Spine: length, 0*07 m. ; breadth, 0*005 m. ; straight; diameter greatest in the
middle and diminishing towards each extremity, the upper one ending in a point.
In section the posterior face forms a depressed curve ; the anterior one is semi-
circular ; along the angles formed by the two there extends, for about one-third
the length from the apex, a double row of denticles, varying in number from seven to
ten on each side. The denticles are broad at the base, connected one to another

/. — Pleuracanthidce.

737

laterally, short, and terminating obtusely, with an elongated cutting edge parallel
to the longitudinal axis. They diminish in size towards the point, and for about
0*004 m. the point of the spine is free. The surface of the spine is uniformly
covered by minute longitudinal striae. In most of the examples the base of the
spine is crushed ; its walls are thin, and the internal cavity comparatively large.

The specimen described as Pleuracanthus alternidentatus, Davis,* from Middleton,
near Leeds, probably belongs to this species. It is slightly more robust and longer,
and the spine in section is rounder ; the principal difference is in the more widely
separated position of the denticles and their being placed along the margins in
alternate series, instead of being opposite. Since the description was written in
1881 other specimens have been found in Yorkshire and also in Staffordshire. The
latter are particularly interesting because they appear to indicate a passage between
the two forms ; the number of denticles is smaller than those of the type specimen
of P. alatus, but greater than those of P. alternidentatus, and they are placed some-
what irregularly. Taking into consideration the new evidence it appears desirable
to regard the two forms as one species, and it is now suggested that Pleuracanthus
alternidentatus be included as a synonym of Pleuracanthus alatus, Davis.

A small specimen from the Deepmine shale at Longton, in Staffordshire, from
the collection of Mr. John Ward, is 0*017 m. in length; one half the length is
armed with a double row of barbs, numbering seven or eight on each side. The
characters of this example appear to indicate its relationship to P. alatus, and it is
probably the spine of an immature fish. It is worthy of note, however, that the
denticulated surface bears a much larger proportion to the whole length of the
spine than in the fully grown specimens, and the distal extremity is not so pointed
(PL lxxiil, figs. 7-9).

Examples of spines found in the Lowmain coal of Newsham occur in the
Atthey collection at the Newcastle Museum. They have a length of 0*045 m.
A double row of denticles extends a distance of 0*017 m., as in the type specimen,
each row containing sixteen to eighteen denticles, longer, recurved, and more
pointed than in the specimens from Tingley or Staffordshire. These character-
istics vary considerably from the original ; but the general resemblance of the
form is sufficiently close to justify its inclusion. The basal extremity of the speci-
men figured is well exposed (PL lxxiii., figs. 10, 11).

Mr. James Thomson has furnished examples collected at Newarthill, Quarter
Hamilton, and other localities near Glasgow, which have about ten denticles in each
row, and approach very near to the type from Tingley (PL lxxiii., fig. 13).

Formation and Locality. — Middle Coal Measures; CannelCoal, Tingley and Middle-
ton, near Leeds ; Knowles Ironstone Shale, Fenton ; and Deepmine Ironstone,

* Quart. Journ. Geol. Soc, vol. xxxvi., p. 328, pi. xn., fig. 3.

5 P 2

738 Davis — On the Fossil Fish- Remains of the Coal Measures of the British Islands.

Longton, Staffordshire ; Watston ; Stonehouse ; Newarthill ; Quarter Hamilton,
Scotland; Lowmain Coal Seam, Newsham, Newcastle- on-Tyne.

Ex coll. — James W. Davis, Halifax ; Museum Literary and Philosophical
Society, Leeds ; John Ward, Longton ; James Thomson, Glasgow ; Atthey Col-
lection, Museum Natural Hist., Newcastle-on-Tyne.

Pleuracanthus erectus, Davis.

(PI. lxxiii., fig. 14-16.)

Pleuracanthus erectus, . . Davis, J. W., 1880, " Quart. Journ. Greol. Soc,"

vol. xxxvi., p. 326, fig. 2 (woodcut).

Spine : length, 0*09 m. ; breadth at the base, 0-008 m., whence the sides converge
in straight lines to an elongated and acute point ; antero-posteriorly compressed ;
section oval, lateral margins produced, forming a series of convex, compressed
projections. The projections have a broad base and are widely separated from
each other. The surface of the spine is striated longitudinally.

Since the description of the original specimen from the cannel coal at Tingley,
other specimens have been obtained from the same locality, which prove conclu-
sively that the similarity to Pleuracanthus Icevissimus, Ag., indicated in the original
description,* and since emphasized by other authors, f was only a generic one.
The species are quite distinct, and may be distinguished by the form and character
of the denticles very readily. In this species they are broad at the base and more
or less rounded, whilst in P. Icevissimus they are long, recurved, and sharply pointed.
The denticulated margin of the spine in the type specimen is 0*055 m. in length,
and on this margin there are twenty-two denticles ; in a specimen of Pleuracanthus
Icevissimus, Ag., from the Lowmain coal, of a similar size and with the same
length of denticulated margin, there are thirty-seven denticles. This comparative
paucity of denticles in P. erectus is characteristic of all the specimens which have
come under observation. In shorter spines, which it is presumed were those of
younger fishes, the disparity is still more marked, and it is equally borne out by
larger ones. A very fine example (PI. lxxiii., fig. 14), which is preserved, along
with others, from the Lowmain coal seam, in the Atthey collection, may be
compared with the specimen of Pleuracanthus Icevissimus, Ag. (PI. lxxii. , fig. 1),
from the same bed. In the latter there are sixty-five denticles on each margin,

* Loc. cit., p. 326.

f R. H. Traquair Proc. Roy. Phys. Soc. Edinburgh, vol. ix., p. 422 ; A. Smith Woodward, Cat. Foss.
Fishes, pt. i., p. 6

/. — Pleurae an thidce .

739

extending over 013 m. : on each margin of the Pleuracanthus erectus there are
only forty-five denticles, and they occupy exactly the same area as the others.

The example last referred to has a length of 0'22 m. ; at a distance of 0"07 from
the basal extremity the lateral diameter of the spine is 0'012 m., and thence it
gradually diminishes to an attenuated point at the distal end, and towards the
base the diameter is also reduced. The spine is oval in section, compressed antero-
posterior^ ; its walls are comparatively thin at the basal end. The internal pulp
cavity appears to have been terminal.

A spine of P. erectus, having a length of 0*21 m., has been found in the shale
immediately above the two-feet coal at Bardsley. Other specimens, not so
perfectly preserved, have been found, and associated with them examples of
P. Icevissimus, Ag. The denticulated margin of the specimen first referred to
occupies 0*11 m., rather more than one-half the length of the spine ; the number
of denticles is thirty-one on each side. A comparison of the more or less
fragmentary spines of the two species exhibits very clearly the difference in
denticulation which has been observed in those from other localities.

Formation and Locality. — Cannel Coal, Middle Coal Measures, Tingley ;
Lowmain Coal Seam, Newsham ; Two-feet Coal Seam, Bardsley.

Ex coll. — James W. Davis, Halifax; Museum of Natural History Society,
Newcastle-on-Tyne ; George Wild, Bardsley.

Pleuracanthus horridulus, Traquair.

(PL lxxil, figs. 22, 23.)

Pleuracanthus horridulus, . Traquair, R. H., 1882, " Geol. Mag.," ser. n.,

vol. ix., p. 541.

Pleuracanthus horridulus, . Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 9.

Pleuracanthus horridulus, . Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 154.

Length of spine, 1 inch ; diameter at base, TV incn I gently arched, tapering
to a point, lower part striated, upper smooth ; upper third of posterior surface set
with a double row of large recurved denticles, eight or nine on each side, placed
alternately with each other.

The specimens referred to were described by Dr. Traquair without figures,
and I have not the originals for reference ; other specimens of this species from

740 Davis — On the Fossil Fish- Remains of the Coal Measures of the British Islands.

Borough Lee have, however, been accessible, and I have before me an example
from the Bone-bed above the Better-bed coal at Clifton, which corresponds exactly
with the Borough Lee specimens. The spine is imperfect, the distal portion
only being preserved; it is O015 in length, and there are eight or nine large
recurved, sharply-pointed denticles ; the surface of the spine is smooth. Except
that the denticles are larger, the spine agrees with the smaller examples of
Pleuracanthus alatus, Davis, and it is quite probable that additional specimens
may show a gradation of the one into the other ; for the present it is suggested
that the specimens should be considered as a separate species.

Formation and Locality. — Bone-bed, Better-bed Coal, Clifton, Yorkshire.

Ex coll. — James W. Davis.

Pleuracanthus cylindricus (Agassiz), Davis.
(PI. lxxiil, figs. 1—4.)

Orthacanthus cylindricus,

Orthacanthus cylindricus,
Orthacanthus cylindricus,

Orthacanthus cylindricus,

Pleuracanthus cylindricus,

Pleuracanthus (Orthacanthus)

cylindricus,
Pleuracanthus cylindricus,

Orthacanthus cylindricus,

Pleuracanthus cylindricus,

Agassiz, L., 1843, " Poiss. Foss.," vol. iii., p. 177,

pi. xlv., figs. 7-9.
Morris, J., 1854, " Cat. Brit. Foss.," p. 335.
Barkas, T. P., 1873, "Coal Meas. Palseont.,"

p. 20, figs. 39-42.
Ward, J., 1875, " Proc. N. Staffs. Nat. Field

Club," p. 217.
Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 331 (woodcut).
Traquair, R. H., 1888, "Geol. Mag.," ser. in.,

vol. v., p. 101.
Woodward, A. S., 1889, " Cat. Foss. Fishes Brit.

Mus.," pt. i., p. 8.
Ward, J., 1890, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 137.
Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 153.

Spine : erect and straight, or with a very slight curvature ; attains a large
size. A specimen in the collection of Mr. Ward, from the Fenton Ironstone shales,
was probably not less than 0*55 m. ; the base is imperfect, but the part preserved,
probably the thickest, has a diameter of 0*025 m. A more perfect specimen has a
length of 0*31 m., and a diameter of 0-018 m., at a distance of 0*2 m. from the apex ;
from this part the diameter of the spine gradually decreases upwards and ends in

I. — Pleuracan thidce.

741

an acuminate apex. In section the spine is more or less round, except at the base,
which is compressed antero-posteriorly ; the extremity is slightly tapering and
rounded. The internal cavity is not terminal, but is open along the posterior
surface for a distance of about 0*04 m. The orifice is large and the walls thin at
the base ; higher, the cavity is reduced to one-third the diameter of the spine, and
gradually diminishes towards the apex. The surface of the spine is covered with
longitudinal striations which sometimes disappear towards the apex. On the
posterior surface is a double row of closely approximating denticles ; they extend
over one-half the length of the spine, and number seventy or eighty denticles on
each side ; they increase in size with the diameter of the spine or towards the base.
The denticles are round near their base, contracting to an obtuse point, directed
diagonally towards the base, and at the same time away from the centre, of the
spine (fig. 1).

A magnificent specimen of the spine of this species is preserved in the British
Museum (Nat. Hist.). It forms a part of the Egerton collection, but unfortunately
there is no record of the locality from which it has been obtained. The matrix is
a hard ironstone shale, and there are a number of molluscan remains on the slab,
Goniatites, Pecten, and other marine forms, together with the remains of a plant,
apparently Lepidostrolus. The spine is 039 m. in length, and the base is imperfect.
Its greatest diameter is 0*018 m. The spine has a slight, graceful curvature, with
smooth surface somewhat deeply striated longitudinally. The denticulated surface
extends 0*1 8 m. along the posterior surface, and on each row there are fifty denticles.
Those situated on the upper part are long recurved hooks, each separated from the
next by a distance equal to the diameter of its own base. Midway along the den-
ticulated surface the denticles are larger, thicker, and stronger ; at the lower part
they diminish again in size and are shorter and more stumpy, where not broken
off in the opposing matrix of the opposite slab. (PI. lxxiil, fig. 2).

The largest examples of this species are from the Fenton and Knowles Ironstone
shales of North Staffordshire. The specimens from the Scotch Measures are smaller,
and some of them, as, for example, one from Quarter Hamilton (fig. 4), in the col-
lection of Mr. James Thomson, of Glasgow, has the rows of posterior denticles
situated wider apart than those described, the intervening area being quite eonvex,
whilst in those from Staffordshire it is flat or slightly concave (fig. 3).

The spine of Orthacanthtcs bohemicus, Fr., from the gas-coal of Nyran, in
Bohemia, probably occupies a position closely allied to this species.

Formation and Locality. — Shale above the Ragmine Ironstone, Fenton ; Knowles
and Chalky-mine Ironstones, Longton ; and Brown-mine Ironstone, Silverdale, in
Staffordshire ; Quarter Hamilton, Scotland.

Ex coll. — John Ward, Longton; James Thomson, Glasgow; Egerton Collection,
Natural History Department, British Museum.

742 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Pleuracanthus Thomsoni, sp. nov.
(PI. LXXIIL, fig. 17.)

Spine : distal extremity absent ; length preserved 0*8 m ; greatest diameter
0*06 m. ; section circular, with round internal cavity. If perfect the spine would
probably be 0'9 m. in length. The denticulated surface which is preserved occupies
0*18 m., and consists of a double row of eleven denticles separated by a distance
of rather more than 0*02 m. ; the intervening space is occupied by a ridge. The
denticles are broad and obtuse, with a broad lateral depression between each.
The spine is slightly curved.

This species approaches most nearly to P. robustus, Davis, in general ap-
pearance. It differs in being thinner in proportion to its length. The denticulated
surface is shorter, and the two rows are closer together. In P. robustus, the den-
ticles extend over half the length of the spine ; in this one they cover little more
than one-fourth. The denticles themselves are short and rounded, whilst in the
former they are closely implanted, recurved, pointed, and extend from the surface
a distance equal to one-half the diameter of the spine.

Formation and Locality. — Above the soft coal in the Red Sandstones at Quarter
Hamilton, Kilmarnock.

Ex coll. — James Thomson, Glasgow.

Pleuracanthus obtusus, nom. nov.
(PI. LXXIIL, fig. 18,)

Phricacanthus biserialis, . . Davis, J. W., 1879, " Quart. Journ. Geol. Soc,"

vol. xxxv., p. 186, pi. x., figs. 16, 17.

Spine: length 0*105m. ; greatest diameter 0.007m. The spine is gently
arched backwards, the exposed part covered with minute longitudinal striations.
In section the spine is circular : from the apex extending 0*05 m. along the pos-
terior surface, there is a right and left row of seven widely separated protuberances
or denticles. In the lower part there is a distance of 0*007 m. between the apex
of two consecutive denticles ; they are broad longitudinally, laterally compressed,
and rapidly converge to a rounded obtuse apex. The denticles are alternate, the
projection on one side being opposite to the depression on the other ; an internal

/. — Pleuracanthidm.

743

cavity, circular in form, extends upwards from the base. The walls of the cavity
forming the base of the spine are thin, and in the specimen now described, they
are crushed.

Mr. A. Smith Woodward* doubtfully places Pleuracanthus biserialis as a synonym
of Pleuracanthus cylindricus, Ag. There is, however, a great difference between the
two spines. The greatest discrepancy is in the form of the denticles ranged on
either side of the dorsal aspect of the spine. In Pleuracanthus (Orthacanthus) cylin-
dricus, Ag. ; the teeth are more or less hooked, pointed, and close together ; but,
in this instance, the denticles are widely separated, rounded, and blunt ; to such an
extent is this the case that the term is scarcely applicable ; they have more of the
character of wavy projections alternately produced ; first right, then left, from the
dorsal surface of the spine ; and it was in consideration of this peculiarity that the
name was chosen. Even if the spine were worn or abraded, which does not appear
to be the case, the great difference in the number of the denticles must distinguish
it from P. cylindricus, Ag., which has six or seven times as many denticles as the
spine now described.

In the original description t of the specimens forming this species attention was
drawn to their resemblance to Orthacanthus, the principal points of difference
being in the curved contour of the spine, and in the peculiar form and large
size of the posterior denticles. During the following year a number of additional
specimens were discovered forming intermediate stages between Pleuracanthus and
Orthacanthus which led to a suggestion that the two genera should be combined
along with Xenacanthus and Diplodus,% and all form only one genus. After con-
siderable care in comparing specimens, it appears probable that Phricacanthus must be
included in the genus Pleuracanthus. The latter now includes not only the straight
spines of Orthacanthus type, but also the curved spines, since allocated to the genus,
and so covers one of the characteristic features of Phricacanthus ; and the denticles
which are now known to be extremely varied in that genus may well embrace the
double row of large, widely separated and alternate denticles of Phricacanthus.
The specific name biserialis is pre-occupied, having been applied to a species of
Pleuracanthus from the Coal Measures of Ohio by Dr. J. S. Newberry § in 1856.
It is now proposed to distinguish the species as Pleuracanthus obtusus, Davis.

Formation and locality. — Bone-bed above Better-bed Coal ; Clifton, Yorkshire.

Ex coll. — James W. Davis, Halifax.

■■• Cat. Poss. Pishes, Brit. Museum, p. 8. 1889.

f Quart. Journ. Geol. Soc, vol. xxxv., p. 186. 1879.

+ Op. ext., vol. xxxvi., p. 325. 1880.

§ Proc. Acad. Nat. Sci., Philadelphia, p. 100. 1856.

TRANS. HOY. DUB. SOC, N.S. VOL. IV., PAET XIV. 5 Q,

744 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

Pleuracanthus serratus, sp. nov.
(PI. lxxiii., figs. 19, 20.)

Spine : length averages 0*04 ; the longest example is 0*07, and the shortest
0*015. An example 0*04 in length is 0*002 in diameter at the base, and diminishes
to a fine point at the distal extremity. The anterior surface is more or less circular
in a section cut across the spine ; the posterior surface is also rounded but to a
smaller extent. A double row of denticles, twenty in number on each side, extends
along the lateral posterior surface in the position shown in fig. 19. The denti-
culated surface extends from the point a distance of 0*025 m. towards the base.
The denticles present the appearance of a series of triangular pendants, the point
of each being suspended from the base of the preceding one ; they are closely set,
and the base, at its lowest and widest part, is equal in width to the height of the
apex of the wedge-shaped denticle. The denticles are largest midway, and
decrease in size both towards the distal and basal extremities.

A considerable number of these small spines have been obtained from the Low-
main Coal Seam. The posterior position of the denticles at once distinguishes
them from small examples of Pleuracanthus Icevissimus, Ag., which frequently occur
in the same beds about the same size. The number of denticles is equal to that
of P. robustus when full grown, but their form is sufficiently distinctive, and they
do not fall in with any of the previously described species.

Formation and Locality. — Lowmain Coal Seam, Newsham.

Ex coll. — Atthey Collection, Museum of the Natural History Society of North-
umberland and Durham at Newcastle-on-Tyne.

Pleuracanthus Woodwardi, sp. nov.
(PI. lxxiii., fig. 21.)

Spine: length 0*25 in.; point and base imperfect; probably 0*025 must be
added at distal end, equal to 0*275 m. without addition to base, or 0*3 in length
if complete; base crushed; at a distance of 0*1 m. from proximal extremity the
diameter is 0*015 m., from which point it tapers to the distal end. In section the
spine is oval, with a flattened anterior surface. The posterior surface has a slight
median ridge, and on each side, extending a distance of 0*1 m. on the part
preserved (or probably 0*12 m. if it were perfect), there is a row of large,

1. — Plcuracanthidce.

745

recurved, acuminate denticles, forty-five in number. The surface of the spine
is smooth or slightly striated.

This species is most nearly related to P. Icevissimits, Ag., but the position of the
denticular row is not lateral but is placed far towards the posterior surface as shown
in fie. 21 a : the denticles are more hooked than in P. kevissimus.

The rows of denticles are, however, not nearly so closely approximated as in
P. cylindricus ; they appear to show a connecting and intermediate link between
the two species, and go a long way to prove their generic identity. I have
appended the specific name Woodwardi in recognition of the services of my friend
Mr. A. Smith Woodward.

Formation and Locality. — Coal Shale, Dalkeith. Candenfoot, Dalkeith.

Ex coll. — No. P 3178a. Enniskillen Collection, Natural History Department,
British Museum. No. P 1730. Egerton Collection, Natural History Department,
British Museum.

Pleuracanthus (Lophacanthus) Taylori, Stock.
(PI. lxxiil, figs. 22, 23.)

A spine from Airdrie (No. 42,035 in B. M. Coll.), perfect at the proximal end,
but wanting the distal one, is 0*20 m. in length. It is slightly curved, 0*01 m. in
diameter at the widest part, more or less circular in section, the antero-posterior
diameter being greater than that between the sides, with a double row of denticles
extending along the posterior surface to a distance of 0*07 m. of the base. The
denticles are short, rather widely separated, slightly curved backwards. The
rows of denticles are separated by a distance equal to half the diameter of the
spine between the anterior and posterior surfaces. The surface is smooth or
slightly ridged in wavy lines. The proximal extremity is rounded with the
terminal orifice open for a short distance along the posterior surface. The
internal cavity higher in the spine is small.

This spine closely resembles that of P. cylindricus, Ag., but has a more distinct
curvature than the spine of that species, and is more especially distinguished by
the wide area separating the two rows of posterior denticles.

The spine, No. P 42,035, appears to be closely related to a spine from the Low-
main Coal Seam at Newcastle, at present in the Atthey collection in the Museum of
Natural History. The Newcastle specimen is 0'24 m. in length, and is slightly
thicker than the one in the British Museum, but in other respects is characterized
by its curved outline and the position of the two rows of denticles (fig. 23).

5 Q 2

746 Davis — On the Fossil Fish- Remains of the Coal Measures of the British Islands.

The spine described by Mr. Thomas Stock* as Lophacanthus Taylori was from
the Lowmain Coal Seam. The writer has not had an opportunity to inspect the
original, but the woodcut with which the description is illustrated indicates a close
resemblance to the spine in the Atthey collection. The section as illustrated by the
woodcut, is different, but that may be perhaps accounted for by the imperfection
of the specimen. The relationship between these spines being so close, I feel
justified in including them under the specific name given by Mr. Stock; but as
I am convinced that they are not generically distinguishable from the spines of
Pleur acanthus, they must be included in that genus.

Formation and Locality. — Coal Measures, Airdrie; Lowmain Coal Seam, Newsham.

Ex coll. — Natural History Department, British Museum ; Mr. Joseph Taylor,
of Shire Moor ; Museum of Natural History, Newcastle.

Pleuracanthus (Compsacanthus) triangularis, Davis.

(PI. lxxiii., fig. 24.)

Compsacanthus triangularis, . Davis, J. W., 1880, " Quart. Journ. Geol. Soc,"

vol. xxxvi., p. 62 (woodcut).

Spine : straight, robust, upper part perfect ; base somewhat crushed ; O063 m.
in length ; greatest diameter 0*005 m. midway between the extremities ; distally it
gradually contracts, and ends in a point. The base is hollow, and the walls are
thin; the internal cavity apparently terminal. The lateral surfaces of the spine
are compressed anteriorly, which gives it a triangular form in section. The
posterior surface, from which springs a single median row of denticles, is rounded.
The denticles are broad at the base, compressed laterally, ending in an obtuse
point.

This spine, which still remains unique, was found in the Cannel Coal of
Tingley; it was included in Dr. Newberry's genus Compsacanthus characterized
by having only a single row of denticles on the posterior surface of the spine.
Compsacanthus Icevis, Newb., is circular in section, and there are a considerable
number of denticles diminishing in size from the lower towards the upper part of
the spine. In this species the number of denticles is small, and the spine is
more or less triangular in section.

Dr. Zittel has expressed the opinion that probably Compsacanthus will be

* Ann. and Mag. Nat. Hist., ser. v., vol. v., p. 217.

f Proc. Acad. Nat. Sci. Philad., p. 100, 1856 ; Kept. Geol. Survey, Ohio, vol. i., pt. ir, p. 332, pi. xl.,
fig. 5, 1873.

/. — Pleuracanthidce. 747

found identical with Orthacanthus,* and Mr. A. Smith Woodward accepts the
same view in cataloguing the fossil-fishes in the British Museum, and places the
genus as a synonym of Pleuracanthus.^

Formation and Locality. — Middle Coal Measures, Tingley, in Yorkshire.
Ex coll. — James W. Davis, Halifax.

Pleuracanthus (Diplodus) equilateralis, Ward.

(PI. LXXIIL, fig. 27.)

Diplodus equilateralis, . . Ward, J., 1889, " Trans. N. Staffs. Inst. Mining

and Mech. Engin.," vol. x., p. 139, pi. n.,
fig. 2.

Diplodus equilateralis, . . Woodward & Sherborn, 1890, " Cat. Brit. Foss.

Verteb.," p. 66.

Teeth: "Base of tooth relatively small, rounded, or oval; concave below,
coarsely pitted with a strong prominent knob or heel-like projection at the
anterior margin. Lateral denticles, two in number, divergent on the same plane ;
they are short, conical, broad for nearly their entire length, when they rapidly
contract ; compressed, equal in length, with their margins finely carinated.
Between the two lateral denticles, at their basal junction, there is a slightly
elevated boss, from which spring two intermediate denticles, equal in length,
compressed, with smooth margins " (Ward).

Formation and Locality. — Shale overlying the Deepmine Ironstone, Longton.
Staffordshire.

Ex coll. — John Ward, Longton.

Genus, Anodontacanthus, Davis.
" Quart. Journ. Geol. Soc," 1881, vol. xxxvii., p. 427.

The spines included in this genus are straight, more or less tapering to a point.
Internal cavity large, terminating at the base without posterior extension of the
opening. Distinguished from Pleuracanthus by the absence of denticles.

* Handb. der Palaeontologie, vol. iii., pt. I., p. 90. 1887.
f Cat. Foss. Fishes, pt. i., p. 2.

718 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands.

The genus is confined to two species from the Cannel Coal of Tingley, in
Yorkshire. A single specimen described as a third species, A. fastigiatus* from
the Blackband Ironstone at Loanhead, in the Carboniferous Limestone series,
near Edinburgh, is considered by Dr. Traquair, who has other specimens, to
belong to another genus, and awaits his further elucidation.

Anodontacanthus acutus, Davis.
(PI. mm., fig. 25.)

Anodontacanthus acutus, . Davis, J. W., 1881, " Quart. Journ. Geol. Soc,"

vol. xxxvii., p. 428, pi. xxn., fig. 10.

Spine: length, 0*6 m. ; breadth, 0*05 m., gradually tapering to a point;
straight, circular in section, with an internal cavity occupying one-half the
diameter of the spine in the middle of its length ; towards the base the walls
become thinner ; orifice terminal. There are no lateral denticles.

Formation and Locality. — Cannel Coal, Tingley.
Ex coll. — James W. Davis, Halifax.

Anodontacanthus obtusus, Davis.
(PI. lxxiii., fig. 26).

Anodontacanthus obtusus, . Davis, J. W., 1881, " Quart. Journ. Geol. Soc,"

vol. xxxvii., p. 248, pi. xxn., fig. 11.

Spine : larger than the preceding one, probably 0*9 m. in length and propor-
tionately thick; oval in section, with the internal cavity much smaller than in
A. acutus ; distal extremity obtusely flattened and circular.

Formation and Locality. — Cannel Coal, Tingley.

Ex coll. — James W. Davis, Halifax.

••: Quart. Journ. Geol. Soc, vol. xxxvii., p. 428. 1881.

PLATE LXV.

ON THE FOSSIL FISH-REMAINS OF THE COAL MEASURES OF THE BRITISH

ISLANDS. — I. PLEURACANTHIDtE.

[1]

EXPLANATION OF PLATE LXV.

Pleuracanthus (Diplodus) IcBvissimus, Agass.

Figure

1. Lower jaws in natural position ; reduced to half diameter.

a. Right lower jaw, under surface. Posterior portion of jaw, apparently divided by centres
of ossification into a series of plates.

b.b. Left lower jaw. Outer margin of the two mandibles thickened by the pressure from the
other side of the upper jaws.

ex. Terminal ossifications forming the snout, and extending between the anterior extremi-
ties of the palato-quadrates.

d. Plate from the left posterior margin of the cranium.

e.e. Cranial plates, probably located anteriorly to d.

2. Pectoral fin (natural size).

3-15. Teeth from various parts of the jaws (natural size).

Formation and Locality. — 1, 3-15, Low Main Coal Seam, Newsham, Northumberland; 2. Cannel
Coal, Tingley.

Ex coll. — Atthey Collection, Museum, Newcastle-on-Tyne ; James W. Davis, Chevinedge, Halifax.

[2]

P L AT E L X V I.

ON THE FOSSIL FISH-REMAINS OF THE COAL MEASURES OF THE BRITISH

ISLANDS. — I. PLEURACANTHIDyE.

TKANS. EOT. DUB. SOC, N.S. VOL. IV., PAET XIV.

[3]

EXPLANATION OF PLATE LXVI.

Vlem ■acanthus (Diplodus) lavissimw, Agass.

Figure

1. Upper jaws (palato-quadrates). Opposite side of specimen represented on Plate lxv. Reduced
to half diameter.

a. Eight upper jaw.

6. Left upper jaw ; each with wide lateral expansion, forming osseous plates, joining
along the median line of the palate.

c. Anterior extremities of palato-quadrates, to which were attached the bones of the

snout (PI. lxv., ex.).

d. Inferior surface of cranial plate exhibited on PI. xlv.

e.e. Inferior surface of plates indicated by same letter on PI. lxv.

Formation and Locality. — Low Main Coal Seam, Newsham.
Ex coll. — Atthey Collection, Museum. Newcastle-on-Tyne.

[4]

11 cuio . J.

Plate LXVL

PLATE LXVII.

ON THE FOSSIL FISH-KEMAINS OF THE COAL MEASUEES OF THE BRITISH

ISLANDS.— I. PLEURACANTHIDjE.

[5]

EXPLANATION OF PLATE LXVII.

Pleuracanthus (? species).
(Natural size.)

Figure

1. Shoulder girdle, with parts of the branchial arches.

a. Left scapular arch.

b. Right scapular arch.

c. Left branchial arches.

Ln >> ») >>

£•2 ), >, »>

c, 3 j) >) »j

c«4 »> »| >>

d. Eight branchial arches.

""i >j >> )>

*•» >> »> >>

^•3 >> )) >>

e. Hyomandibular bone.

/. ? Base of attachment for the spine.

g. Gill-rakers (stemmatoid ossicles) derived from the gill-arches.

Formation aud Locality. — Low Main Coal Seam, Newsham, Northumberland.
Ex coll. — Atthey Collection, Museum, Newcastle-on-Tyne.

2. Bones of upper surface of the cranium.

a. Parieto-frontal plates.

b. Occipital.

c. Lateral occipitals.

d. Postero-lateral plates, completing the posterior margin of the cranium.
e.f. Intermediate plates between the parieto-frontals and the lateral plates, g. h.

g. h. Lateral plates ; g. on the left side in fig. 2 is covered by the displaced plate d.
i. Anterior plates over the snout.
x. Small median hexagonal plate.
or. Orbits.

2a. Eestoration of No. 2. The letters above apply to this figure.

3. Underside of the occipital plate.

Formation and Locality. — Low Main Coal Seam, Newsham, Northumberland.
Ex coll. — William Dinning, Newcastle-on-Tyne.

[6]

PLATE LXVIII.

ON THE FOSSIL FISH-REMAINS OF THE COAL MEASURES OF THE BRITISH

ISLANDS.— I. PLEURACANTHIDiE.

EXPLANATION OF PLATE LXVIII.

Pleuracanthus (? species).
(All figures natural size.)

Figure

1. Eight lower jaw. Internal surface.
la. ,, ,, ,, External surface.

2. Articulating extremity of lower jaw.

3. The same of another specimen.

a. Articulating process.

b. Angular bone.

c. Dentary bone.

4. Pleuracanthus (Diplodus) lavissimus, Agass. Exhibiting the serial arrangement of the teeth.

a. Teeth of upper jaw.

b. Teeth of lower jaw.

5, 5a. Osseous fragment, with articulating surface.

6. Another example, with articulating extremity.

7. Osseous plate.

8. Occipital plate.

9. Pterygopodium (clasper) of the ventral fin.

a. Clasper.

10. Pterygopodium, (?).

Formation and Locality. — All ^except fig. 4 from Low Main Coal Seam, Newsham. Fig. 4, Thin
Bed Coal, Burnley, Lancashire.

Ex coll.— Figs. 1, 2, 5, 6, 7, 8, 9, W. Dinning, Newcastle-on-Tyne ; fig. 3, Atthey Collection,
Museum, Newcastle-on-Tyne ; fig. 4, George Wild, Bardsley, Lancashire.

[8]

Trans. R.Dub. S.,N.S.,Vol.IV.

Plate I .XVIII.

PLATE LXIX.

ON THE FOSSIL FISH-EEMAINS OF THE COAL MEASUEES OF THE BEITISH

ISLANDS. — I. PLEUBACANTHIDvE .

[9]

EXPLANATION OF PLATE LXIX.

Pleuracanthus (Diplodus) lavissimw, Agass.
(Keduced to half diameter.)

a. Right ramus of lower jaw.

a. ' Articulatory surface.

b. Anterior extremity of left ramus of lower jaw.

c. Dentary surface, with teeth.

d. Extremity of the palato-quadrate.

e. j

> i., ii., in., rv. Bones of the branchial arches.

f. )

g. Detached gill-rakers.

Formation and Locality. — Low Main Coal Seam, Newsham, Northumberland.
Ex coll. — Atthey Collection, Museum, Newcastle-on-Tyne,

[10]

PLATE LXX.

ON THE FOSSIL FISH-EEMAINS OF THE COAL MEASURES OF THE BRITISH

ISLANDS.— I. PLEUR AC ANTHILL.

TRANS. EOT. DUB. SOC, N.S. VOL. IV., PAET XIV.

[11]

[EXPLANATION OF PLATE LXX.

Pleuracanthus (Diplodus) Icevissimus , Agass.

Figure

1. Head considerably crushed, with spine (natural size).

a. Right ramus of lower jaw, showing arrangement of teeth in situ.

b. Lower jaw; left ramus.

c. ? Hyomandibular.
d. d. Cranial plates.

e. Spine.

2-9. Examples of so-called " Stemmatodus " (enlarged).

Formation and ocality. — Low Main Coal Seam, Newsham, Northumberland.
Ex coll. — Atthey Collection, Museum of Natural History, Newcastle-on-Tyne.

[12]

Trans. R.Dub. S

Plate LXX.

Irans. ELDub. S.,N. S.,Vol.IV. Plate LXS

PLATE LXXL

ON THE FOSSIL FISH-REMAINS OF THE COAL MEASURES OF THE BRITISH

ISLANDS.— I. PLEURACANTHHm

[13]

EXPLANATION OF PLATE LXXI.

Figure

1. Pleuracanthus (Diplodus) Icevissimus, Agass., exhibiting the posterior part of the head
together with spinous bones of the haemal or neural arches, and inter-spinous bones
(Eeduced to half diameter.)

a. Lower jaw.
b. b. Cranial plates dissociated.

c.

Vertebral spines (? neural), with enlarged base.

d.

Inter-spinous rays.

e.

Surapophysial ray.

t.

Teeth.

2. Inter-spinous ray

Natural size.

3.

4. Surapophysial ray.

I 1

5. Teeth. Enlarged.

Formation and Locality. — Low Main Coal Seam, Newsham, Northumberland.

Ex coll. — William Dinning, Newcastle.

[14]

Trans. R. Dub. S., N. S.,Vol. IV.

Hate LXXI

J.W Davis drr.W.H CrowtWhth „

West Newman, Imp

PLATE LXXII.

ON THE FOSSIL FISH-EEMAINS OF THE COAL MEASUKES OF THE BRITISH

ISLANDS. — I. PLEURACANTHIDiE.

[15]

EXPLANATION OF PLATE LXXII.

*

Figure

1. Pleuracanthus Icevissimus, Agass.

3-9. Pleuracanthus lavissimus, Agass.

1. Ragmine Ironstone, Fenton. Ex coll. — John Ward.

3. Cannel Coal, Tingley. Ex coll. — James W. Davis.
4, 5. Arley Mine, Burnley. Ex coll. — George Wild.
6, 7. Lowmain Coal, Newshani. Ex coll. — Newcastle Museum.

8. Shattleston, Glasgow. Ex coll. — James Thomson.

2. Pleuracanthus cylindricus, Agass. Fenton, Staffordshire. Ex coll. — P. 6692, British (Natura

History) Museum.

10-14. Pleuracanthus robustus, Davis.

10, 11, 14. Cannel Coal, Tingley. Ex coll. — James W. Davis.

12. Knowles Ironstone Shale, Fenton. Ex coll. — John Ward.

13. Lowmain Coal, Newsham. Ex coll. — Newcastle Museum.

15. Pleuracanthus Wardi, Davis. Bagmine Ironstone, Fenton. Ex coll. — John Ward.

16. Pleuracanthus undulatus, Davis. Thin-bed Coal, Burnley. Ex coll. — G. Wild, Manchester

Museum.

17. Pleuracanthus tenuis, Davis. Better-bed Coal, Yorkshire. Ex coll. — James W. Davis.

18-20. Pleuracanthus denticulatus, Davis.

18. Better-bed Coal, Yorkshire. Ex coll. — James W. Davis.

19. Lowmain Coal, Newsham. Ex coll. — Newcastle Museum.

20. Bardsley, Lancashire. Ex coll. — George Wild.

21. Pleuracanthus Howsei, Davis. Lowmain Coal, Newsham. Ex coll. — Newcastle Museum.

22, 23. Pleuracanthus horridulus, Traq. Better-bed Coal, Clifton, Yorkshire. Ex coll. — James W.
Davis.

N.B. — Fig. 2 in this Plate has heen drawn by mistake instead of the specimen of P. lavissimus, referred to in the text.

[16]

Plate LXXH.

West. Newman, imp

Trnns R.Dub. S.,N.S..V,il IV.

Plate LXXI1

PLATE LXXIII.

ON THE FOSSIL FISH-EEMAINS OF THE COAL MEASUEES OF THE BEITISH

ISLANDS. — I. PLEUEACANTHID2E.

[17]

EXPLANATION OF PLATE LXXIII.

Figure

1-4. Pleuracantlms cylindricus (Agassiz), Davis.

1. Eagmine Ironstone, Fenton. Ex coll. — John Ward.

2. ? Ex coll.— P. 1735, British (Natural History) Museum.

3. Knowles Ironstone, Longton. Ex coll. — John Ward.

4. Quarter Hamilton, Scotland. Ex coll. — James Thomson.

5-13. Pleuracantlms alatus, Davis.

5. Tingley, Yorkshire. Ex coll. — James W. Davis.

6. Middleton, Yorkshire. Ex coll. — Museum, Leeds.
7-9. Deepmine Shale, Longton. Ex coll. — John Ward.

10-12. Lowmain, Newsham. Ex coll. — Newcastle Museum.

13. Quarter Hamilton, near Glasgow. Ex coll. — James Thomson.

14-16. Pleuracantlms erectus, Davis.

14. Lowmain, Newsham. Ex coll. — Newcastle Museum.
15, 16. Cannel Coal, Tingley. Ex coll. — James W. Davis.

17. Pleuracantlms Thomsoni, Davis. Quarter Hamilton, Kilmarnock. Ex coll. — James Thomson.

18. Pleuracantlms obtusus, Davis. Better-bed Coal, Clifton, Yorkshire. Ex coll. — James W.

Davis.

19, 20. Pleuracanthus serratus, Davis. Lowmain Coal, Newsham. Ex coll. — Newcastle Museum.

21. Pleuracantlms Woodwardi, Davis. Candenfoot, Dalkeith. Ex coll. — P. 3178, British (Natural
History) Museum.

22, 23. Pleuracanthus Taylori (Stock), Davis.

22. Coal Measures, Airdrie. Ex coll.— No. , 42,035, British (Natural History)

Museum.

23. Lowmain Coal, Newsham. Ex coll. — Newcastle^Museum.

24. Pleuracanthus triangularis, Davis. Tingley, Yorkshire. Ex coll. — James W. Davis.

25. Anodontacantlms acutus, Davis. Cannel Coal, Tingley, Yorkshire. Ex coll. — James W. Davis.

26. Anodontacantlms obtusus, Davis. Cannel Coal, Tingley. Ex coll. — James W. Davis.

27. Pleuracanthus (Diplodus) equilateralis, Ward. Deepmine Ironstone, Longton. Ex coll. — John

Ward.

[18]

IWns. R.Dub. S.,N. S., Vol. IV.

Plate LXX1II.

J.WDavis dir.W.H.CrowtKer.lith.

West, Newman, imp

J W Davis tfcr W.H Ciwther Uth.

Went.Newman,ixnp